sentences:  At about the same time, Gaelic tribes from Ireland invaded the north-west, absorbing both the Picts and Britons of northern Britain, eventually forming the Kingdom of Scotland in the 9th century.The south-east of Scotland was colonised by the Angles and formed, until 1018, a part of the Kingdom of Northumbria.Ultimately, the population of south-east Britain came to be referred to as the English people, so-named after the Angles.