Although often attributed to a certain 'Nennius', the 'Historia Britonum' ('British History') is not the work of a single author but a compilation which grew by accretion--one series of legends after another added to the original core--and was repeatedly rewritten over several centuries. Modelled after Irish chronologies and containing much fabled material, it offered the only history of Wales in early medieval times. It was attributed to both Nennius and Gildas to give it intellectual authority. Geoffrey of Monmouth drew upon it for his 'History of the British Kings' because it preserved ancient stories and legends of the British. Also, it contains the earliest mention of the name Arthur in its stories of an early British king. This manuscript is the most complete copy. The British Library's manuscript has at the end of the 'British History' the earliest copy of the Welsh Annals. Each page is aid out in three narrow columns, with one line for each year (abbreviated 'an' for 'annum'), most remaining blank. This is the first page of the annals, starting with the year 447. The first entry reads 'Days as dark as night,' followed by the alteration of the date of Easter by Pope Leo, the birth of Brigit and death of Patrick. In the third column, the long entry for 516 tells of Arthur's victory at the Battle of Badon, in which he 'carried the cross of Christ upon his shoulders for three days', meaning his shield bore a cross.