Anglo-Saxon literature developed between 449 BC and 1066 AD as various Germanic tribes invaded and settled in Britain following the decline of the Roman Empire. Oral traditions and poetry were an important part of Anglo-Saxon culture, addressing themes like heroic deeds, riddles, and solemn expressions. The language evolved from Old English dialects to Middle English following the Norman conquest in 1066. Key literary genres included elegaic, heroic and riddle poems, which often utilized devices like appositives, litotes, alliteration and kennings. Famous works included Beowulf and riddles from the Exeter Book.