Bede recorded that King Vortigern invited the Angles to come to Britain to fight for him against the Picts. Angeln was centred around Schleswig but its precise extent is subject to discussion. Bede recorded that the Angles moved lock, stock and barrel leaving Angeln to be colonised from North and South by the Jutes and the Saxons, respectively. Subsequently word got back to the "new" Angles that there was more than enough land to go around so many of them came too. The Jutes settled in Kent, The Saxons in Wessex, Essex, Sussex, Middlesex and subsequently in Somerset. The Angles in the lands north of theThames, where the North Folk and the South Folk of the East Angles are still remembered in the names Norfolk and Suffolk. Anglian influence also extended into South East Scotland as far as Edinburgh. I'm remembering all this from a long time ago, so I'd suggest you check it out from other sources. I can't quite remember who populated Mercia although I think they were Angles as well.