St. Gildas, Venerable Bede and The Anglo-Saxon Chronicles

In "De Excidio Britanniae", St. Gildas (sometimes called "The Wise"), a 6th century British monk, denounced in the most aggressive language possible, the terrible wickedness of his times. He is the only substantial source which survives from the time of the Anglo-Saxon conquest of Britain, and the best source prior to the much more impressive work of the Venerable Bede (who completed his "Ecclesiastical History of the English People" almost 200 years later, in 731).

 Could this monk be Bede? The picture, made 500 years after Bede lived, comes from a copy of Bede's book about the Christian church leader St Cuthbert.

The first page of Bede's History of the English Church and People. It begins with a decorated initial letter B (from 'Britain'). The book was made in the 800s.

 A page from the [C] text of the Anglo-Saxon Chronicle. This entry is for 871, a year of battles between Wessex and the Vikings.

The initial page of the Peterborough Chronicle.

Answer:

What did St. Gilda's write? When?

What did Bede write? When?

Who wrote The Anglo-Saxon Chronicles? When?

What is the conection between these works?