Excerpts from Books and Wikipedia
Pope Gregory chose Augustine to head a mission to Britain in 596 with forty monks. The monks landed in 597 and King Ethelbert later converted to Christianity. The monk Paulinus was sent to Northumbria, and converted King Ethelbert's son-in-law, King Edwin, in 627. The story is told by Bede in "Ecclesiastical History of the English People" that Pope Gregory saw fair-skinned slaves in Rome and was told they were Angles. He replied, ""Non anglii sed angeli" (Not Angles but angels) and he decided to send a mission to England. [Furtado: 1001 Days]