The Anglo-Saxon Chronicle has also been useful for historical research, as it preserves a chronology of early English history. The surviving works include poems, biblical translations, homilies, philosophical essays, and legal documents. Old English was the language of the Angles, a Germanic people who arrived in Britain around 500 AD. It was not yet a literary language, since no written language had yet been developed in England. Instead, scribes made use of Latin, which was the official language of the Roman Empire. During the 11th century, however, monks began writing poems in Old English, which led to its development into a literate language. Old English ceased to be used for everyday purposes after the 13th century, when English replaced it as the language of administration and literature. After the Norman conquest of 1066, William the Conqueror ordered that English should be the official language of government and law. This led to a surge in interest in English poetry, since officials needed reliable guides on how to write correctly. Many French poets came to England to learn about British culture and customs, which they could then incorporate into their work. Another factor contributing to the importance of old English literature is the fact that it provides evidence of early English spelling and grammar.