"What did the second line do?" Topic

I'm reading about early Medieval battles and the accompanying maps show armies drawn up in 2 or sometime 3 parallel lines. Then the flanks are protected by cavalry, archers or whatever.

So did the second line just reinforce the first? I see no reference to them maneuvering. Or to "passage of lines."

Do we even know?

Not sure really, but in game world, I send off levy/ weak troops to pin, engage, absorb those initial missile volleys. Unlike wargame missile troops, they probably would not be as effective later shooting.
As the battle unfolds my commander and his huscarls, then engage and rout the enemy!
Then there is much plunder and rejoicing!
Those levy troops don't contribute saga dice anyway.

The second line stops enemy breakthroughs and allows broken troops from the first line to rally behind it.

I'd query those maps, myself.

The cases where I know of successive lines, it was generally because someone wanted to form three "battles" side by side but got jammed up somehow.

We're talking all-star games, remember: very talented individual players, but just about no practice on working together as a team.

Depends on the battle. Sometimes, missile armed troops were sent in front of the main force deliberately, to soften, hopefully, the enemy battleline (the French tried it at Poitiers); then came the main force and, finally, the reserves.

In other cases, it was a result of the lay of the land. At las Navas de Tolosa (1212) neither army had the room necessary to deploy in a single battleline, so they did it in three lines, which had the added benefit of absorbing the momentum of enemy charges, while allowing your own to counterattack.

It could also be a consequence of a battle that wasn't expected by either side. Not exactly encounter battles -those were uncommon and commonly part of an ambush- but unexpected. Then, the formation of the march was integrated into the deployment, to avoid delays that could cause chaos and defeat.

Finally, there are some scholars that propose that, at least in Christian countries -most of Europe back then-, there was a conscious attempt to represent the trinitarian nature of Christian worldview in how armies were deployed. So, as God was a Trinity, and battle was considered a God's Judgement of the fairness of your cause, deploying your forces in three lines was a conscious hommage to God, and a no-so-subtle way of telling Him that you were the Good Guys and would appreciate Him showing it by conceding you victory in the field of honour. It is somewhat more complicated, of course, but that is the gist of the hypothesis.

They help push, especially with shield walls, etc. Also to fill in gaps due to casualties. A single line is a fragile thing unless weaponry is at a huge advantage. Two handed swinging weapons are a big exception though.