Rhiwallon ap Cynfyn of Powys
Rhiwallon ap Cynfyn of was born about 1000 in Powys, Wales.  He died in Battle of Mechain, Montgomeryshire, Wales.

 Gwladus ap Rhiwallon of Powys
Gwladus ap Rhiwallon of was born about 1041 in Powys, Wales.

 Sionet ap Rhiwallon of Powys
Sionet ap Rhiwallon of was born before 1073.