I remember that once I had besieged a settlement, which was the capital, and the general was the king. I killed down his whole army, as the poor king didn't had the upgraded weapons and plate armors which my troops had. And as a result my whole army was still with me.
At last, only HE was left, his bodyguard were slain down the second-layer of the walls. I surrounded the central plaza, and began 'Executing' him by putting my cannon in front of him. I fired one volley, which missed the target. Suddenly he charged and managed to break my lines and kill 3-4 of my men. He retreated to the second layer, but my knights were already waiting for him (this was because the Plaza was already full by infantry and archers, and there was no space left for knights to come). He also managed to kill 10-20 more of them, but finally we opened the gate of the third layer, and my good old Armored Sergeants came in (I had saved them from over 200 years, and didn't upgrade their armor), and they finally managed to kill him.