The Roman legions withdrew from Britain in about 410 CE, by which time there is already evidence that groups of Germanic people were living alongside the native Romano-British population, probably as auxiliary troops. Over the next 150 years, a period from which almost no records survive, they were evidently greatly added to by immigration, and began to create a new social structure and culture that spread to control most of Britain, and began to divide it into a number of Anglo-Saxon kingdoms.