Cathal was a dedicated naval captain of Kul Tiras during the Great War. He served under Janus DeMeza until the man's defection and rebellion. Afterwards, Cathal's career took him up through the ranks until he became captain. As captain, he was posted to Braent to oversee the city's annexation to Kul Tiras. When Kul Tiras was attacked by DeMeza, the Esoteric Order and the Benefactors, Phorcys ensured a regime change. Due to the regime change, a new regency council was formed and Cathal was sent orders to renounce Braent's annexation.
When Cathal informed Duke Leopold that he was to withdraw in the midst of a siege, the Duke reacted poorly. He rammed Cathal over the battlements, to his death, so that Cathal would be unable to carry out the orders to withdraw, and to keep the renounciation of the annexation a secret for as long as possible.