Medieval English refers to the forms of the English language spoken and written during the Middle Ages, roughly from the 5th to the late 15th century. This period saw significant changes in vocabulary, grammar, and pronunciation, influenced by Old English, Norman French, and Latin. The most notable form of Medieval English is Middle English, which emerged around the 12th century. It is characterized by a mix of Germanic and Romance language elements, making it quite different from both Old English and modern English. Famous works from this period include Geoffrey Chaucer's "The Canterbury Tales."