Family: Gwgon ap Bleddyn, arglwydd of Cas-wis / Gwenllian ferch Philip (alias Gwenllian Gwys) (F200004211)

Gwgon ap Bleddyn, arglwydd of Cas-wis (1090- )

Gwenllian ferch Philip (alias Gwenllian Gwys) (1100- )

Gwallter ap Gwgon, lord of Cas-wis (1130- )

Madog ap Gwgon (1130- )

Cydifor ap Gwgon (1130- )

Trahaearn ap Gwgon, arglwydd of Brecon (1130- )

Thomas ap Gwgon (1130- )