born: ca 1197


His father handed over the Sussex lands of Bramber and Knepp to him in August 1218, so it is probable that he came of age in that year.

died: 2nd May 1230


William succeeded his father as Lord of Abergavenny (right), Builth and other Marcher Lordships in1227. Styled by the Welsh as "Black William" he was imprisoned by Llewelyn ap Iorwerth in 1229 during Hubert de Burgh's disastrous Kerry (Ceri) campaign. He was ransomed and released after a short captivity during which he agreed to cede Builth as a marriage portion for his daughter Isabella on her betrothal to David, son and heir of Llewelyn. The following Easter, Llewelyn discovered an intrigue between his wife, Joan, and William.  Supported by a general clamour for his death, Llewelyn had William publicly hanged on 2nd May 1230.