The Anglo-Saxon period (450-1066 A.D.) marked a time of significant societal change in England as kingdoms emerged from Roman control, characterized by invasions, conflicts, and a shift from Celtic to Anglo-Saxon dominance. Key figures like King Alfred of Wessex unified the Anglo-Saxons against Viking invaders, leading to a sense of national identity. The period ended with William the Conqueror's invasion and the Battle of Hastings in 1066, fundamentally altering the course of English history.