The history of Englan is similar to the history of Britain before the arrival of the Saxons. It begins in the prehistoric during which time Stonehenge was erected. At the height of the Roman Empire, Britannia (England and Wales) was under the rule of the Romans. Their rule lasted until about 410, at which time the Romano-British formed various independent kingdoms. The Anglo-Saxons gradually gained control of England and became the chief rulers of the land. Raids by the Vikings were frequent after about AD 800. In 1066, the Normans invaded and conquered England. There was much civil war and battles with other nations throughout the Middle Ages. During the Renaissance, England was ruled by the Tudors. England had conquered Wales in the 12th century and was then united with Scotland in the early 18th century to form "Great Britain". Following the Industrial Revolution, Great Britain ruled a worldwide empire, of which, physically, little remains, however its cultural impact is widespread and deep in many countries of the present day.