In the mid-sixth century, nine of these kingdoms in the "neck of Britain" were ruled by Coel Hen's descendants... who intermarried with the rulers of the other four realms -- Gododdin, Lleuddiniawn, Ystrad Clud, and Novant.

Altogether, they were called the Men of the North by their distant kin in Gwynedd (later Wales) to the south. Sometimes these kings allied against a mutual enemy, but more often they bickered and feuded among themselves.