"Why did the Peninsular War go on for so long? " Topic

Ok, and at the start let me say I am NOT trying to start a flame war or anything similar, but why, when most of the Napoleonic campaigns were done and dusted in a matter of months, did the British success in Spain and Portugal take 5 or 6 years to succeed?

Everything I read paints the French as hopeless and losing every battle (slight exaggeration) but it took to 1814 for the invasion of France.

So, potted summaries/views welcome please.

The French were far from hopeless – and Spain isn't easy campaigning country.

You simply can't march across it as quickly as you can Germany.

Plus whereas Wellington won all of his battles, the other allied armies didn't, which, along with the general French skill at manoeuvre, often meant scurrying back to Portugal to maintain lines of communication with Lisbon.

Wellington was cautious, but then he had the only British Army in existence, so losing it wasn't an option.

They totally outnumbered Wellington's forces right up to the end of the war. Guerilla wars tend to be protracted and that, plus battles against Spanish forces, that we generally hear little about, kept Boney's Marshals separated and vulnerable.

Geography/terrain/climate, a determination to fight on within the civilian population, a safe base to fall back on in emergency, an external source both of supply and regular forces and a distracted, overextended, occupier…..a recipe for a protracted war whether Iberia or South East Asia……..

Dear Marc

All the other Napoleonic battles were fought against POWERS that were willing to accept the decision of the battlefield. The Spanish were not. That is, one climactic battle and there was really no enemy army left. Further, Napoleon in none of these wars meddled with the ruling dynasty, or seriously attempt to change the existing culture. This he attempted in Spain with the Deposition of the Spanish Bourbons. As moronic and incompetent as they were, and as much as the people of Spain ridiculed and hated them, they were still THEIR royal Family and gained a popularity they did not deserve at all. Then moving his own brother from Holland to Spain, like upgrading a mere civil servant was adding insult to injury.

The other problem was the Spanish forces who ran away a lot, which meant they cold re-assemble at another time, rather than standing in for one big pitched battle and losing all.

Finally we must say something about the French. Unlike the Frei-Corps in Germany and the resistance under Stein and others, the war in Spain was a true guerilla war. This was still winnable, except the French were far too humanitarian to do what was required. They were unwilling to massacre everyone to massacre the guerillas.

I agree with what's been said above. In addition:

It was a war of the elephant and the whale. The French could move enormous resources across their land border with Spain, but could never prevent the Royal Navy from taking the strategic initiative by landing smaller numbers of troops and supplies anywhere they pleased around the peninsula.

The land was poor and the terrain bad. "In Spain, big armies starve and small armies get beaten." Supplies to feed the armies had to come from outside the theater, by sea. So merely building up the greatest possible number of soldiers could not win the war for the French.

The French could not overcome the combination of British strategic initiative, Spanish popular resistance and good defensive terrain, but neither could the Allies decisively defeat the French.

In the end, the French Empire was defeated on other fronts, in Russia in 1812 and in Germany and France 1813-14, and these greater defeats made it impossible to continue to support a stalemated war in Spain.

Whereas other European campaigns led to the lost of entire armies, neither side in Spain was able to do the same. Each side was able to avoid the loss of entire armies, and the both lived to fight another day.

Plus, in the grand strategic realm, Spain was a side show. Essentially, for the French it was an economy of force mission. Its real efforts were in central Europe where Prussia, Austria, and Russia were serious threats to France. The UK was never a serious ground threat to France -- it's real contribution was its sea blockade and the money it paid to its allies to support their ground campaigns.

It also took a while for Richard Sharpe to get the South Essex and Chosen Men into shape; but once he did then it was only a matter of time before the Frenchies were relieved of command ;-)

"All the other Napoleonic battles were fought against POWERS that were willing to accept the decision of the battlefield." true, but with the notable exception of the Russians of 1812!

The Spanish did not know they had been beat.

The French never understood that they would gain the Spanish with:

a) Put into power Ferdinand with French advisers and if possible married with a french noble woman.

b) Respect the Catholic church, if possible given them some money and lands (more than they have).

Those were imho the two pivots that the Spanish used to sustain a war without ending.

My two cents…

Amicalement
Armand

A bunch of people seem to be answering the question, "Why didn't the French win?" by the OP was, "Why did it take the British so long to win?"

If nothing else, the French could easily march replacements into Spain across the Pyrenees and they had a much larger army (and population) to draw from. It made little sense for Napoleon to declare defeat in Spain and withdraw. Spain would have been able to raise larger armies with complete control of its territory and they and the British would have advanced to the frontier of France. Not a big advantage, especially with the threat of the Royal Navy turning the flank of the French border defenses in conjunction with a ground assault. The French had no incentive to give up and simply couldn't be beaten so long as they could push in replacements.

As usual, there was not only one reason. Napoleon's plan for Spain and Portugal was relatively simple: to close both countries to British commerce and transform them into net contributors to France's war effort against Britain. It's not clear when Napoleon decided to get rid of the Spanish Bourbons and replace them with a French client. Probably as early as February 1807 he started to plan for the overthrow of the Spanish Bourbons. Some circumstancial evidence -off hand commentaries to his ambassador in Spain- points that maybe as early as November 1805 he wanted to solve the "Iberian problem", i.e. occupy Portugal and force the Continental Blockade and reorganize the Spanish government in way that it would be more efficient, militarly speaking. It's not sure that he plan to overthrow the Bourbons just yet, though.

His intelligence on Spain was faulty. He believed that the disgust of the Spanish elites with Godoy and with the whole conspiracy-ridden Spanish monarchy would make a transition relatively peaceful. He warned his generals in Spain to watch for demonstrations and popular uprisings, but he thought the forces that he had sent to Spain and Portugal between November 1807 and February 1808 would be enough to smash any rebellion. The Spanish rebellion of May-June 1808 caught him by surprise. It was more general that he had imagined it could be. Still worst, from his perspective: it wasn't just a popular uprising. Spanish regular army forces joined the rebels. Moreover, the Spanish local elites acted decisively by creating a political alternative both to Joseph Bonaparte and to Ferdinand.

Mind that the rebellion was eccentric, in the literal sense of the word: it mostly concentrated in the periphery of the country. That hurt the French effort from the beggining. Spain in 1808 was bereft of many roads of any military value, and none of the few that existed conected laterally. All of them started in and from Madrid. Against an enemy with a clear line of political command, i.e. a functional government, that centrally located network could have acted in benefit of the French. However, against an enemy that actually consisted of dozens of political centers -local juntas- which considered themselves the authentic representatives of the nation, only served to disperse the French initial efforts to quell the rebellion.

Then came Bailen. It was a surprise for everybody. Nobody actually expected that what was considered a third-rate army would have been able not just to defeat, but forced to surrender, to an army of the biggest power in Europe. Try to imagine what would be the reaction in Britain or the United States if a whole battalion would surrender to the Taliban. It wouldn't be more shocking that what happened when the news of Bailen reached London or Paris. For the Spanish was a boost of morale that reinforced the will to fight even after the disasters of 1808-1809. Even when Valencia fell in January 1812 the memory of Bailen served to harden the Spanish resolve to continue the war. It's like what Concord/Lexington did for the American Revolution. It was more than physical.

It wasn't just Bailen. It came after the victories at El Bruch in Catalonia and then the failed foray of Mortier in Valencia and the fracas in first siege of Zaragoza. It erased the stain of Cabezón, Medina de Rioseco and Puente de Alcolea.

There was another problem for the French. In 1808, the Spanish fortified cities were located in the periphery, in the coastline and in the frontier with Portugal. Remind that the main enemies of Spain until then were the British and the Portuguese. The French hadn't the resources needed to invest and capture all of them. That, together with Bailén, gave the Spanish the time needed to consolidate the rebellion. Later, when Napoleón entered Spain and thoroughly defeated the Spanish and forced the British to retreat, served as rally points and as a strategic tool to disperse French efforts. Some sieges were very short, but others, like Gerona (nine months), Ciudad Rodrigo (2 months) or the blockade of Cádiz (2 years) consumed a lot of scarce French resources and time.

The insurgency on the French strategic rear was also part of the equation. To put it into perspective, the French were forced to devote almost 70,000 men to control the area comprised between Vitoria-Burgos-Valladolid-Palencia-Santander, plus Navarra. In that region operated no more than 8,000, probably less, permanent partisans. When Suchet attacked Tarragona, he could use 21,000 men only from his army in Aragón. Another 22,000 were left behind protecting his lines of communications through Señorío de Molina-Zaragoza-Jaca, with France. Napoleón actually ordered two divisions from the Army of Catalonia to support Suchet (that, by the way, forced a pause in counter-insurgency operations that gave a welcomed breathing space to Catalonian rebels).

Last but not least, the French were forced to deal with a very well led professional army -the British, and from 1810 the new Portuguese army- that could operate from secure bases -especially after finishing the Lines of Torres Vedras- and which had a extraordinary strategic mobility thanks to the Royal Navy dominion over the seas around the Peninsula. And that while also dealing with Spanish armies that didn't matter how many times were defeated appeared again and again. Apparently, nobody had passed the memo to the Spanish that said that once you were decisively defeated you just didn't came back for more.

Bottom line, is that the Peninsular war lasted so long because Napoleon never could or would devote the resources necessary to deal with all those problems in a single campaign season. And the problem only got worse once he decided to invade Russia.

My two cents!

It was that big cannon Sophia Loren dragged across Spain.

Basileus,

Two cents very well used, if I may say so!

Basileus, as always, sets out a very good case.

One of the most interesting chapters in Oman's history of the war is where he describes the nature of the terrain in the Iberian peninsula, it is obvious from this that Spain and Portugal are not really the types of places you want to commit large bodies of troops to operating.

From personal observation I would have to agree with Oman! :o)

Sideshows tend to go on and on. No one really wanted to commit the forces that would be needed to end it. The British could always claim to everyone else that they were doing something, see we have troops on the continent, while they spent more money on the fleet and supporting which ever ally was currently fighting the French.

Bah. Sharpe won the war. Case closed.

Great thread Antonio! (smile)

Amicalement
Armand

You could make a case for two (or more) Peninsular Wars.

The first lasts up to Corunna. The second ends as St Sebastian.

If you accept this, the war(s) aren't that long.

I agree with all that, which is also very interesting, but to return to the original question

"Why did the British army take so long to win:"

There are lots of reasons, but some are:

-1808-1809 was optimistic intervention by the British to support (the supposedly huge, enthusiastic armies of) their ally Spain. 1810-11 was just hanging on in there in total isolation: that's why Wellington had to contend with so many pessimists (like Churchill 1940-early 41); that's why Napoleon couldn't envisage that the French could screw up
- the British Expeditionary Corps was outnumbered about 10: 1 by the French until Napoleon started to withdraw troops in later 1811 the British started to build them up as part of fight back allied to Russia, and Wellington could trust his British-trained Portuguese who boosted his troops into a serious force.
- the British army was always worried about being cut off in a vast country
- Wellington had very few cavalry and couldn't risk being caught in the plains by the French; he always had to "go home" to the (Portuguese) mountains
- He had few/no skilled sub-commanders capable of successful independent action (Crauford, Hill, … who else??)
- non-veteran British troops were extraordinarily incapable of looking after themselves on campaign (posting pickets, making bivouacs, getting food, not getting blind drunk, looking after its horses, etc
- non-veteran British officers were almost all amateurs with no training (think Crimean war)
- campaigning was just very complicated in a huge, poor, devastated country; Wellington slowly built up an immense logistical system with tens of thousands of wagon and mule drivers on British pay (as he had in India in similar circumstances)

Because of Wellington's astonishing long list of successes we tend to forget that the British army had a deservedly lousy reputation in 1808 after a series of recent disasters that led to overseas expeditions capitulating to (non-European!!!!) troops, following very mediocre performance in the French Revolutionary Wars (no one noticed Maida in 1806). There as no general staff, there was no transport corps, no brigading or divisions, virtually no engineers, artillerymen and artillery drivers from separate government depts.
The Duke of York's reforms – back to (Prussian) basics for the line + shooting practice + proper light infantry (Light Brigade) together with Wellington's management skills – and patience – produced a result that surprised other nations just as much as Spanish resistance did.

Simples. Other campaigns were of relatively short duration because the "French" won spectacular victories in the first half of the Napoleonic Wars, breaking the will of the enemy to fight on. Wars are expensive and if your armies are beaten in the field, a peace treaty that offers no regime change and the preservation of the bulk of your economy and way of life is a good way out.

The Spanish and the Russians didn't see it that way – e.g., regime change was being forced on the Spanish – and so they decided the continued, wholesale destruction of their country was worth fighting on for (helped, of course, by the vast nature of of their territories which hindered the supply and communications of their enemy more than it did them). Later, of course, other states (e.g., Prussia and Austria) also decided the risk was worth taking again.

Also, everyone talks about "the French" but in fact, the Allies were fighting an "Imperial" force consisting of not only French but also units from many other states including, most notably, Poland and the Italian, German and Dutch states. How far would the French have got without them? As for the "British" Army (which obviously included other nationalities also) it was most certainly, the decisive force for the Allies, just like a star football player. But without the various Spanish Armies, the other players in the team, pinning down forces elsewhere, what would the outcome have been?

I recommend "The Spanish Ulcer: A History of the Peninsular War" by David Gates.

Thanks guys – especially those who considered my OP which I did not word very clearly – as the British won, I was trying to identify key reasons why it took them so long to win (not why the French lost). The British were so good, and so successful, that I was trying to understand why they didn't wrap it up far quicker.

It is a key reason that I don't game the theatre as the British are regarded as so superior that most rules lead to victory for them (IMHO – not the point I wanted to discuss here), and so it feels like a gap in my Napoleonic knowledge.

Thanks for all of the above inputs – most welcome.

"The British were so good, and so successful, that I was trying to understand why they didn't wrap it up far quicker."

They were successful because Wellington (and Moore) understood the strengths and (major) weaknesses of the Army they commanded, so they had to pick their moments and manage their resources carefully, which took ages. They weren't successful because the British Army was inherently brilliant, it clearly wasn't.

As well as the other points made above, the difficulty of the terrain for keeping cavalry in the field must also have played a part.

If you won a battle, it was rarely feasible to pursue the enemy to destruction because you simply didn't have sufficient cavalry to do so.

This also limited the number of guns; in most Peninsular battles the guns-per-thousand-men ratio was substantially lower than those seen in battles in the main theatre. For example, at Vimeiro Wellington had 1 gun per thousand men, versus the more usual 2 to 4 seen in other theatres. This in turn meant few bloody slugfests that left the loser too weakened to fight on. The majority of French losses were to sickness and the guerrilleros, and took a long time to accumulate.

They weren't successful because the British Army was inherently brilliant, it clearly wasn't.

Yet so many wargame rulesets try to re-create British victories by assigning bonuses to British troop qualities – +1 to morale for Steadfast Roast Beef Eaters, +1 to firepower for Brown Bess Bonus, +1 to charge for Crazy Jocks, etc. Without all those bonuses, it's hard to be Wellington.

So far we have identified two key areas:
1. Richard Sharpe (Rifleman).
2. Sophia Loren (Artillery commander).

Did Weliington really have a say in this campaign? He always seemed to have a bit part in the TV series, Sharpe, and Sophia's great film.

I also think that Nelson's victory at Trafalgar (1805) and the role of the Royal Marines were essential to the 1814 success.

The French forces always outnumbered the British. While Wellington could defeat them piecemeal while they were divided, he had to retreat if they threatened to combine against him. And that was all the easier for the French if tehy were being forced back on their lines of communication.

Personally I do mainly Spanish against French.

Bonuses for crazy jocks and other people Bonuses for crazy jocks and other people with funny hats (7th & 23rd Fusiliers) is obviously silly.

But British infantry should get a +1 bonus for firing
a) they were the only ones to practise (with live ammo too)
b) the best units like 43rd and 52nd could get off 4 shots a minute compared to 3 from the French and 2 from the Spanish.
c) the British main tactic of short range volley (or two) and then bayonet charge deserves attention in any rules.

And British cavalry should have a first charge bonus +1: bigger horses, high morale, tally ho mentality.

The down side is (lack of) controllability: British cavalry just could not manoeuvre in large numbers like the French. Crucially, it really should be very difficult to stop other British cavalry joining a charge someone else starts. It should be very difficult to get either British infantry or cavalry and especially Guards to use common sense and stop after victory. At virtually every battle, some unit blew it and nearly cost Wellington the battle by going out of control and chasing after a defeated enemy (first line)- or at Vitoria booty. The French – and KGL – by contrast, were professionals.

Too damm hot, poor road system, a desert that is well worth seeing. As Martin Rapier said they had to use resources very carefully.

Wellington and the French commanders faced an interesting set of conditions that are almost impossible to reproduce in a wargame (it would be a very good game that did but unfortunately we now have the advantage of hindsight and can just copy Wellingtons approach).
Heavily outnumbered with not the best available troops and allies that were difficult to deal with, Wellington made some good strategic moves that provided oportunities to take on the French armies on his terms, before they could concentrate their forces against him. And he found positions which suited the fighting techniques of his army. But he had to be cautious and know when to duck back behind his defensive line. He couldn't afford another Corunna – it would have finished him. Also these successfull battles provided him the political support to increase his army. And so he slowly wore down the superior French army until he was on virtually equal terms and could finally begin his big offensive. But even then, things went slowly as the French went on the defensive and Wellington had to prise them from their fortresses and strongpoints.
No great set piece battles then but a long slow 'mind game' to constantly stay one step ahead of the opposition.

The Spanish campaign lasted six years because 7 Spanish armies (almost without supplies, the British logistics support was invaluable for hard-pressed Spanish armies) were in inferiority to the respective 7 (allies?) French army corps (Italians, Dutch, Germans, Poles, etc …) plus another French reserve Corps, so the war dragged on.
The small English expeditionary army ventured timidly on the peninsula 3 times, and then always had to retreat to recover from the casualties and fright.
Finally after the Russian campaign, Napoleon so weakened his army of Spain that he was decisively defeated at the Battle of Vitoria by the Spanish, Portuguese and English.
That is the summary of why the campaign of Napoleon in Spain lasted six years, with 200,000 french casualties.
Very good question!

Teodoro Reding

Because of Wellington's astonishing long list of successes we tend to forget that the British army had a deservedly lousy reputation in 1808 after a series of recent disasters that led to overseas expeditions capitulating to (non-European!!!!) troops, following very mediocre performance in the French Revolutionary Wars (no one noticed Maida in 1806). There as no general staff, there was no transport corps, no brigading or divisions, virtually no engineers, artillerymen and artillery drivers from separate government depts.
The Duke of York's reforms – back to (Prussian) basics for the line + shooting practice + proper light infantry (Light Brigade) together with Wellington's management skills – and patience – produced a result that surprised other nations just as much as Spanish resistance did.

Was it the Army that was 'lousy'? Or was it the poor logistical organisation, political/strategic and leadership quality?

Oh! You forgot Alexandria.

Regiment for Regiment, The British army were and still are, excellent.

Lets not blame the tool eh!

Paul :)

Yes all those rules with those +1s for British this and British that- they really get my goat too. Ridiculous.

Now +1 for French in column (irresistable impetus), +1 for French artillery (because they were so professional), another +1 for French artillery (because they can form a grand battery), +4 for Old Guard (because, er well, you know, they were obviously the best troops of the period)…. Well that's all clearly based on unarguable historical fact n'est pas?

A bit like -1 for 1806 Prussians (because they have rigid linear tactics and so can't skirmish), or -1 for post 1806 Prussians (because they are all Landwehr or reserves), or -1 for any Austrians at any period, ever (because er well obviously the French always beat them….) Fine with all that too.

Back to the OP- if everything you've read indicates the French are hopeless in the Peninsula, I'd love to know what you've been reading. All the serious British historians from Oman and Fortescue onwards give praise to the fighting qualities of the French army and its troops.

My tuppence worth about why victory took so long is that for almost all the period strategic success for the British was counted as just keeping a substantial army in the field. While Wellington's repeated victories helped keep the British in the Peninsula, and helped keep everyone else fighting- actually driving the French from Spain was, to put it mildly, an extremely remote if not impossible prospect until 1813-14.

This thread is longer than the Peninsula War ..

err Sene, my OP did say "slight exaggeration". I know the French/allies were good for the period, it is just I struggled (casually) to comprehend how Napoleon's campaigns in Europe were done and dusted in months, yet the British took 6 years to win (even with their +1 modifiers ).

But the replies above have been helpful. STill not sure there is much incentive for me to game any of the battles yet, but maybe enough for me to go a bit deeper on my reading.

Napoleon's campaigns in Europe were done and dusted in months, yet the British took 6 years to win

The War of the Third Coalition (1803-1806) and the war of the Fourth Coalition that followed (1806-1807) took much longer than "months"; and the Austrians, Russians and then Prussians had a lot more men and resources involved in the fight, than the British had in the Peninsula.

By the way, last time I checked, Spain and Portugal are both in Europe.

Iberia was Napoleon's Vietnam…….granted a phrase used far too often by historians, but there are similarities

His forces were far more powerful than the locals' (Spain and Portugal) and the "British". However the geography mitigated against conventional warfare, the weaker forces could retire to a safe haven and had a secure supply base too, the population refused to admit defeat and fought on in a guerilla war. A dominant power maintained supply and reinforcements (here overland and of course via the Royal Navy, rather than the Ho Chi Minh trail and China/USSR).

The big difference of course, US forces never did lose a single conventional battle against NVA or VC (few near things but no Salamancas or Vittorias here)

Both conflicts suggest that dreaded "mission creep"

Was it the Army that was 'lousy'? Or was it the poor logistical organisation, political/strategic and leadership quality?

One of the problems the British army operated under during the 18th and early 19thC was an orgnaisational structure that was designed to constrain its efficiency. Indeed, even today the British have a Royal Navy and Air Force but no Army, because in peace time Parliament has to re-authorise the existence of the army every year! Things like putting the artillery under the control of the Board of Ordinance were political decisions to weaken the power of the army. Why would they do this? Because of the experiences of the Civil Wars of the 17thC.

England briefly became a republic because of a military victory and the presence of a powerful army. I am sometimes asked by Americans I meet why England isn't a Republic today, I tell them "Imagine how much fun America would be if the country was under a military government run by Jerry Falwell, rather put us off the idea old boy" – most understand. Following the Restoration there was a deliberate move to limit the power of the army. In the popular mind the army was not rehabilitated until the First World War. Read Kipling to understand the attitudes of the public in the later Victorian period.

In many ways it is a wonder that the British did as well as they did during the period 1690-1860.

I`m not sure what the answer to this one is …did they all argue about the rules ?

Weird thing our Constitution (we do have one, just not in writing!) Army and Air Force (not Navy)swear;

"I… swear by Almighty God that I will be faithful and bear true allegiance to Her Majesty Queen Elizabeth II, Her Heirs and Successors, and that I will, as in duty bound, honestly and faithfully defend Her Majesty, Her Heirs and Successors, in Person, Crown and Dignity against all enemies, and will observe and obey all orders of Her Majesty, Her Heirs and Successors, and of the generals and officers set over me."

No mention of democratically elected Parliament, Prime Ministers etc………..loyalty is to the Monarch (suits me!)

{(:-ĭ )

Marc the plastics fan:

I know the French/allies were good for the period, it is just I struggled (casually) to comprehend how Napoleon's campaigns in Europe were done and dusted in months, yet the British took 6 years to win (even with their +1 modifiers grin).

The other side of the coin could be why, that part of most powerful army in Europe took six years in trying to kick a tiny army out of the Peninsula, but be beaten and have their country invaded by them?

+1 To Seneff, his reply says it all afaic.

Paul :)

Are they worth gaming?

Yes, if the historical result was a defeat for the Spanish, then set the Spanish player`s victory conditions to be to achieve a better result than their historical counterparts.

Games (historical battles) do not have to be balanced to be playable.

Did the British Government really go looking for the "win" until 1811/1812, if by "win" you mean a series of military defeats of the French and their removal from the Peninsula by military means? The French Regime in Spain claimed to be the legitimate authority. It therefore had to demonstrate this by removing all opposition to it's rule, it had no other choice.

To "win", all the British Government had to do was have a force in the Peninsula and to support Portugal and the Juntas. The very existence of this force and of the Juntas was enough to question the legitimacy of the French and a useful method of tying up French resources. So, I don't think there was a plan to "win" by crushing the French in the Peninsula until it became obvious that Napoleon was going to go to war with Russia and the campaigns leading to Cuiadad Roderigo and Badajoz.
I'm not saying that there weren't discussions and options, but the British commitments for her forces were worldwide, and the goings on in the Peninsula were not the main effort, so comparisons with Central European campaigns are a bit lopsided in my opinion. Plus, everything said above about the actual difficulties involved in moving and fighting are still highly relevant at the army level.

A better question is why didn't Napoleon go back after the Danube campaign of 1809 and finish the thing himself??

A better question is why didn't Napoleon go back after the Danube campaign of 1809 and finish the thing himself??

I think Napoleon, immediately prior to commencement of the 1810 campaigning season, felt he'd earned himself a nice break, and on a personal level wanted to concentrate more on the succession of his own dynasty rather than war [divorce and remarriage].
The Spanish regular forces had been effectively dispersed and/or contained by 1810, and the Anglo-Portuguese were a small force, both of which Napoleon felt could be comfortably handled by his Marshalate. Massena was considered second only to Napoleon in terms of independent command in 1810 – who better to crush Wellington and the Anglo-Portuguese in Portugal.

Agree with mon ami Ligniere!
It was a matter of "love".
That Austrian Princess was poison to him same as Talleyrand (smile).

Amicalement
Armand

"The other side of the coin could be why, that part of most powerful army in Europe took six years in trying to kick a tiny army out of the Peninsula, but be beaten and have their country invaded by them?"

IIRC Napoleon did kick the British army off the peninsula while he was there. They came back.

I think Napoleon, immediately prior to commencement of the 1810 campaigning season, felt he'd earned himself a nice break, and on a personal level wanted to concentrate more on the succession of his own dynasty rather than war [divorce and remarriage].

Well lets assume that Napoleon with the full weight of the Imperial Guard and the Grand Armée and comes back to Spain in 1810. He decides to deal with Wellington and leads the Third Invasion of Portugal rather than the Duc di Rivoli. Can he do any better when faced with the Lines of Torres Vedras? Or does his army starve more quickly instead? Certainly the damage to his prestige is huge if he fails.

IIRC Napoleon did kick the British army off the peninsula while he was there. They came back.

He did no such thing, nor did he perceive he had done such a thing at the time. It is worth reading up on what Moore was trying to do (divert French attention by threatening their lines of communication) and what Napoleon was trying to do (destroy the British Army in situ). Moore succeeded and Napoleon failed (no blame to him, Moore was never actually "in range"). Napoleon never got near enough to 'kick' Moore at all.

138SquadronRAF,
If Napoleon were in command of the Army of Portugal, the cooperation from Soult, operating from Andalusia into Estremadura, lacking for Massena, might have been more forthcoming. That might have made Wellington's job somewhat more precarious.
Nobody on the French side knew of the existence of the lines of Torres Vedras, but Napoleon wouldn't have been interested in an extended, drawn out campaign. I suspect, his efforts would have been to entrap/pin Wellington close to the Portuguese/Spanish border, whilst Soult maneuvered into his rear. Had this maneuver been feasible, Wellington could, quite possibly, have never have reached the safety of the lines of Torres Vedras.