This is not a great battle but probably a more historic one that I had (and enjoyed, purely for the historical aspect). I was going to post my two-front bridge battle but someone already posted a similar one.

1st Crusades, Anatolia -

The Pope has called a crusade to retake Jerusalem from the infidels. England, the Holy Roman Empire, and Milan take up arms and march towards Constantinople, meaning to cross over to Asia Minor from there. The Milanese were the first to cross, and - mirroring history - their army was composed of many pilgrims and camp followers (in game terms this would translate to roughly 10 peasant and peasant archer units, with the rest of 10 units made up of 1 general, 2 knights, 2 light cavalry, and the rest men-at-arms).

The Turkish Crown Prince, in command of an army of Turkomen horse archers, spied the Milanese crossing the Bosphorous and planned an ambush in some hills along the road to Iconium, and waited.

The Crusaders finally approach, with darkness coming on soon, looking for a place to camp. As the road wound down into a shallow valley below the hills, the Turkomen horsemen emerged from the hills and quickly forced the crusaders down into the valley. The valley resembled a shallow bowl and as the crusaders tried to form some form of defense at the bottom, the Turkomens rode around them and lined the lip of the "bowl", and started firing down into the valley full of men.

The knights and their retainer sergeants tried valiantly to charge up the hill, but were cut down like grass by massed arrow fire from all directions. Unable to attack the fleet-footed archers on top of the valley, the surviving Frankish cavalry retreated back to the bottom of the valley to attempt a final stand to protect the pilgrims. However, the mass of pilgrims themselves made it difficult for the actual fighting men to redeploy, and all the time with arrow storms raining down on them.

Eventually the crusaders saw the futility of staying where they were and attempted a breakout to the west, by going back up the road they came. The swift Turkomen cavalry followed them on both sides and shot them down. The road back was littered with the dead and dying, and as the English and German armies passed by the site of the battle weeks later, the English were so affected by the sight that they turned back, leaving only the Germans to carry out the Pope's mission (in game terms, they just kept going in circles for some reason until they lost all their men and the army was disbanded).