England in the Middle Ages concerns the history of England during the medieval period, from the end of the 5th century through to the start of the Early Modern period in 1485. When England emerged from the collapse of the Roman Empire, the economy was in tatters and many of the towns abandoned. After several centuries of Germanic immigration, new identities and cultures began to emerge, developing into kingdoms that competed for power. A rich artistic culture flourished under the Anglo-Saxons, producing epic poems such as "Beowulf" and sophisticated metalwork. The Anglo-Saxons converted to Christianity in the 7th century and a network of monasteries and convents was built across England. In the 8th and 9th centuries England faced fierce Viking attacks, and the fighting lasted for many decades, eventually establishing Wessex as the most powerful kingdom and promoting the growth of an English identity. Despite repeated crises of succession and a Danish seizure of power at the start of the 11th century, it can also be argued that by the 1060s England was a powerful, centralised state with a strong military and successful economy.