Quote Originally Posted by Cadwallon
Stakes. Any bowmen with stakes are the best defenders.
Agreed. As the English I had to keep Hamburg horribly undermanned while my concentrated the bulk of my forces south toward the remnants of the HRE. That castle had 1 unit of longbows, 1 levy spearman, 1 family member, and 2 dismounted feudal knights. Being such as tasting target for Denmarked, I was besieged a couple of times by half-stacks comprising mostly of war clerics, crossbowmen, and town militia (maybe with some artillery thrown in).
1 placed my longbowmen's stakes right in front of the gate and had a unit of dismounted knights right behind it. In the beginning of battle, I sent my longbows up onto the walls and my other unit of dismounted knights. The AI had a ladder and a tower, so (obviously) the ladder got there first. By the time my knights had dispatched the troops sent on the ladder, I shifted them to the other side of the gate were the tower was just about to hit.

Once the gates broke down the AI usually charges with the unit that sent the ram, followed by a cavalry charge. The entire attack never got past the gate and the area outside was littered with bodies thanks to my longbowmen. I would only take minor losses to my 2 dismounted knights. Those stakes transformed any unit behind it into some sort of invincible phalanx. Really, this shouldn't happen because in campaign battle you can't put spikes on roads... but you can on paved city streets.... Either way that is a strategy that works every time.