The name was acquired from the Germanic tribe, the Angles, first mentioned in Tacitus (c. AD 100) as Anglii. They invaded Roman Britain in 477 and gave their name to Anglia (East Anglia) where they first landed. They then went on to found the influential kingdoms of Mercia and Northumbria. Over subsequent centuries, the words Engle, Englisc (pronounced -sh) and Engaland came into use. By the beginning of the 11th century, the name of the country had been firmly established as England.