In 3 campaigns I lost 1 siege. I was Byz and i was sieged in Bucharest by the Hungarians. I had 4 crossbows and a general and was attacked by 1 general, a couple of hungarian nobles, 1 croosbow and 5 or 6 spear militia. The city had just a palisade wth1 gate. I managed to kill 60% of the enemy though. Since I started using all cav armies with the Byzantines in mid 2nd campaign I have never lost a battle.