Short answers, pulled from the story.
The Angles originated from the Angeln peninsula on the Baltic Sea coast of Schleswig-Holstein, in what is now northern Germany. Bede, who died in 735, recorded that their homeland, which he called Angulus, lay between the province of the Jutes and the Saxons and was still unpopulated in his own day. The area is still called Angeln today and forms a triangle between modern Flensburg, the city of Schleswig, and Maasholm on the Schlei inlet.
As Germanic settlers in post-Roman Britain, the Angles were the dominant group, and the settled territory came to be called Engla land, meaning the land of the Angles, in Old English. The people themselves used the term Engle, from which both England and the adjective Englisc, meaning English, derive. Latin and Celtic speakers initially used Saxons as the umbrella term for all Germanic settlers, but the Angles adopted Engle as their own collective identity.
The earliest surviving mention of the Angles appears in chapter 40 of the Germania by the Roman historian Tacitus, written around AD 98. Tacitus calls them the Anglii and places them beyond the Semnones and Langobards, who lived near the lower Elbe, grouping them with six other tribes who worshipped the goddess Nerthus. The name may also appear in Latinised form as Anglii in this same work.
After settling in Britain, the Angles founded the kingdoms of Northumbria, East Anglia, and Mercia, which were among the kingdoms of the Anglo-Saxon Heptarchy. Early Anglian settlement also produced the sub-kingdoms of Bernicia, Deira, and Middle Anglia, which by the seventh century had consolidated into Northumbria and Mercia. Northumbria at its greatest extent reached as far north as what is now southeast Scotland, including Edinburgh, and south to the Humber Estuary.
According to Bede, Pope Gregory I (who died in 604) saw a group of Angle children from Deira for sale as slaves in the Roman market and made a Latin pun on their name: "Bene, nam et angelicam habent faciem, et tales angelorum in caelis decet esse coheredes," meaning they have an angelic face and ought to be co-heirs of the angels in heaven. Bede reports this encounter moved Gregory to send a Christian mission to Britain. The wordplay worked because Anglii (Angles) closely resembled the Latin angeli (angels).
Schleswig has yielded prehistoric materials dating apparently from the fourth and fifth centuries, including a large cremation cemetery at Borgstedt, between Rendsburg and Eckernförde, containing urns and brooches that closely resemble objects found in pagan graves in England. The deposits at Thorsberg moor in Angeln and at Nydam preserved weapons, ornaments, clothing articles, agricultural implements, and at Nydam even ships, allowing scholars to reconstruct Anglian material culture just before the migration to Britain.