The saints' lives portray King Gwynllyw as an active and merciless warrior who attacked and raided nearby kingdoms. The "Life of Saint Cadoc" describes him as "very partial to thieves, and used to instigate them somewhat often to robberies" but the "Life of Saint Gwynllyw" insists he was a just and fair ruler. These raids included attacking his northern neighbour Brycheiniog. In one such raid described in "Life of Saint Cadoc" Gwynllyw accompanied by 300 men abducted Gwladys (Gladys) the beautiful daughter of King Brychan of Brycheiniog, as Brychan had refused to let him marry her. She was one of Brychan's famous twenty-four children. A pitched battle occurred which was only stopped by the intervention of King Arthur and Cai and Bedwyr who supported Gwynllyw and his war band in the battle. This tale of abduction seems similar to elements in the tale "Culhwch and Olwen" and other Arthurian stories indicating it originated in bardic stories. This is the earliest reference to Arthur in a Saint's life. According to the "Life of Saint Gwynllyw" this battle never occurred and the marriage was actually accomplished peacefully.