The most common form of warfare during the period. Each area had a number of fortified places the local troops, and much of the local population, would take refuge in when a hostile army appeared. The area could not be conquered until these fortified places were taken. Basically, the attacker surrounded the fortress, walled town or city, and attempted to prevent the enemy within from breaking out as well as stopping any relief force from breaking in. While attempts were made to breach the walls and assault those inside, more effort went into negotiation (trying to talk the besieged into surrendering).