Dun Aengus. Aengus was son of Umhor (Iuvor), the SE England Belgic king, related to Gann (Commius), who led his sons and followers in alliance with the descendants of Gann in the Celtic invasion of the West of Ireland. They erercted their invasion beachhead forts up along the Clare, Galway and Mayo coast, Aran and Achill Islands. These are still named after the Belgae (Dun Belg, Caher Belg) or their Invasion Leaders (Dun Aengus, Dun Irgus, Murmhac Mil, Dun Iumhor, Dun Mod and Dun Oghil.