Rhodri the Great (in Welsh, Rhodri Mawr; occasionally in English, Roderick the Great) (c. 820–878) was the first ruler of Wales to be called 'Great', and the first to rule most of present-day Wales. He was called King of the Britons by the Annals of Ulster. His son Cadell ap Rhodri conquered Dyfed, which was later joined with Seisyllwg by Rhodri's grandson Hywel Dda to become Deheubarth. Like his grandfather, Hywel would come to rule to bulk of Wales.