Derry (dĕrˈē) [key] or Londonderry lŭnˌdəndĕrˈē, lŭnˈdəndĕrˌē city (1991 pop. 95,371) and district, NW Northern Ireland. Much of the district is hilly, except for the low cultivated plain along Lough Foyle. The district was dominated for many centuries by the O'Neill family. The city, on the Foyle River near the head of Lough Foyle, is the second most important in Northern Ireland. It is a naval base and seaport with industries that include food processing, textiles and apparel, computer products and services, and chemicals.
The city grew up around an abbey founded in 546 by St. Columba. It was burned by the Danes in 812. In 1311 Derry was granted to Richard de Burgh, earl of Ulster. When it was turned over (1613) to the corporations of the City of London, the name was changed to Londonderry; the older name was restored for the local government authority in 1984. The old town walls are well preserved. In the siege of Londonderry by the forces of James II (beginning in Apr., 1689), it was held for 105 days under the leadership of George Walker; a triumphal arch, a column, and one of the town gates commemorate the siege. In the late 20th cent. the city was the scene of conflict between Catholics and Protestants.
The city contains a Protestant cathedral (built 1628–33; restored 1886–87), a Roman Catholic cathedral, and a monastery church (founded 1164). Magee Univ. College in Derry is affiliated with Queens Univ., Belfast.