Short answers, pulled from the story.
The Kingdom of East Anglia existed from the 6th century to 918 CE. It was organised in the first or second quarter of the 6th century and was absorbed into the Kingdom of England in 918 after the East Anglian Danes submitted to Edward the Elder.
Rædwald, a member of the Wuffingas dynasty, was the most powerful East Anglian king. Bede described him as overlord of all kingdoms south of the Humber, and the Anglo-Saxon Chronicle names him Bretwalda. He defeated and killed the Northumbrian king Æthelfrith at the Battle of the River Idle in 616.
Sutton Hoo, near Woodbridge in eastern Suffolk, is the site of a sumptuous ship burial that scholars widely believe commemorates or contains the remains of Rædwald, king of East Anglia. The burial mounds there, along with those at Snape, point to a centre of Wuffingas royal power.
The Danish Great Heathen Army landed in East Anglia in 865, wintered there, and returned in 869 to winter at Thetford. King Edmund was defeated in battle at Hægelisdun and killed, after which the Danes installed puppet-kings and East Anglia ceased to be an independent kingdom.
Edmund was the king of East Anglia who was defeated and killed by the Danes at Hægelisdun in 869. He was buried at Beodericsworth, later renamed Bury St Edmunds in his honour, and became venerated as a martyr and patron saint of the region.
The East Angles spoke a dialect of Old English. Linguists Kortmann and Schneider argue East Anglia can claim to be the first place in the world where English was spoken, as the Anglo-Saxons settled the region possibly as early as the start of the 5th century.