Question: What manuscript survived the medieval Welsh poem consisting of a series of elegies to the men of the Brittonic kingdom of Godddin,  who fought a battle around AD 600 between a force raised by the Gododdin, a Brythonic people of the "Hen Ogledd" or "Old North" of Britain, and the Angles of Bernicia and Deira?
Sentence (from "Y Gododdin"): It is traditionally ascribed to the bard Aneirin and survives only in one manuscript, the Book of Aneirin.
Relevant evidence: Yes