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 "Mynyddog Mwynfawr"): Mynyddog Mwynfawr (variant orthographies include: Old Welsh "Mynydawc Mwynvawr"; Middle Welsh; "Mynyddawg Mwynfawr") was, according to Welsh tradition founded on the early Welsh language poem "Y Gododdin" (attributed to Aneirin), a Brittonic ruler of the kingdom of Gododdin in the Hen Ogledd (southern Scotland).
Relevant evidence: No