The term Anglo-Saxon comes from two Germanic tribes, the Angles and the Saxons. This period of literature dates back to their invasion (along with the Jutes) of Celtic England circa 450. The era ends in 1066, when Norman France, under William, conquered England. Much of the first half of this period, prior to the seventh century, at least, had oral literature. A lot of the prose during this time was a translation of something else or legal, medical, or religious in nature; however, some works, such as "Beowulf," and those by period poets Caedmon and Cynewulf, are important.