Downpatrick, town, Newry, Mourne, and Down district, southeastern Northern Ireland. Downpatrick is located where the River Quoilé broadens into its estuary in Strangford Lough (inlet of the sea). The town takes its name from dún (fortress) and from its association with St. Patrick. It is the Dun-da-leth-glas (Fortress of the Two Broken Fetters) of Irish chroniclers. Formerly a MacDunleary stronghold, it was seized in 1177 by the Anglo-Norman adventurer John de Courci and served as his headquarters until 1203. At nearby Saul, St. Patrick began his mission in Ireland in 432 and is reputedly buried in the grounds of the Church of Ireland Cathedral, which was built in 1790. The town is a market centre and has the county administrative offices. The remains of the Cistercian Inch Abbey, founded by de Courci in 1180, are 2 miles (3 km) north. Pop. (2001) 10,320; (2011) 10,874.