The medieval kingdoms of Portugal and León faced a common Muslim enemy on their southern frontiers. They also viewed each other as potential threats, along a boundary which grew in length as the Muslims were pushed back. Military preparedness was in these circumstances a major preoccupation of the monarchs in the two kingdoms. Offensive forces were needed for continued territorial expansion, and defensive forces were needed to protect lands that had already been gained, whether from Muslim counterattack or from inroads (...) by the Christian neighbor. (shrink)
