Who was the brother of Tostig Godwinson that overthrew Gruffydd, Rhiwallon, and Bleddyn?
Rhiwallon ap Cynfyn Rhiwallon ap Cynfyn (c. 1020 – c. 1069 ) was a Welsh King. the son of Cynfyn ap Gwerstan and brother of King Bleddyn of Powys. Through his mother Angharad, he was half-brother to King Gruffydd ap Llywelyn as well. Following the 1063 invasion of Wales by Harold and Tostig Godwinson that overthrew Gruffydd, Rhiwallon and Bleddyn jointly received Powys and Gwynedd on condition of faithfully serving Edward the Confessor "everywhere by water and by land".
Gruffudd ap Cynan Gruffudd ap Cynan (c. 1055 – 1137), sometimes written as Gruffydd ap Cynan, was King of Gwynedd from 1081 until his death in 1137. In the course of a long and eventful life, he became a key figure in Welsh resistance to Norman rule, and was remembered as King of all Wales. As a descendant of Rhodri Mawr, Gruffudd ap Cynan was a senior member of the princely House of Aberffraw.