Around the time of the battle described in the poem "Y Gododdin", c. 600, Common Brittonic was believed to be transitioning into its daughter languages: Cumbric in North Britain, Old Welsh in Wales, and Southwestern Brittonic, the ancestor of Cornish and Breton. Kenneth Jackson concludes that the majority of changes that transformed British into Primitive Welsh belong to the period from the middle of the fifth to the end of the sixth century. This involved syncope and the loss of final syllables. If the poem ultimate dates to this time, it would have originally been written in an early form of Cumbric, the usual name for the Brythonic speech of the Hen Ogledd; Jackson suggested the name "Primitive Cumbric" for the dialect spoken at the time. however, scholars date the poem to between the 7th and the early 11th centuries, and the earliest surviving manuscript of it dates to the 13th, written in Old Welsh and Middle Welsh.