For one thing, relatively small forces were involved - at the Battle of Hastings (in 1066), which resulted in the Norman conquest of England, about 10,000 Normans overcame about 7,000 English (the population of England was about 2.5 million at that time). The 'big' wars were seldom among Europeans, but involved fighting off external threats from invaders such as the Muslims, the Magyars and the Mongols. Moreover, these wars of resistance reflected the unity of Christendom in that many states often combined their forces.