sentences:  He had a brother, Clydog, who was probably the younger of the two.Hywel was later reputed to have married Elen, the supposed heiress of King Llywarch of Dyfed, which connection was subsequently used to justify his family's reign over that kingdom.Hywel's father Cadell had been installed as King of Seisyllwg by his father, Rhodri the Great of Gwynedd, following the drowning of the last king in the traditional line, Gwgon, in 872.