The siege was the most common type of battle fought during the Middle Ages. Medieval armies and commanders tended to avoid pitched battles unless forced into them by circumstances. Medieval warfare and its concentration on sieges can thus be considered the ultimate in positional warfare as success usually lay with control of castles and strong points and the terrain they dominated.
In the early medieval period, there was not much in the way of new construction of fortifications and therefore not many examples of siege warfare. As the peoples of Europe began to organize themselves and nations and strongmen emerged there was a renewed focus on defensive fortifications that led to the castellation of Europe beginning in the tenth century, which was substantially completed by the end of the twelfth century.