Cork (Irish: Corcaigh) is the second largest city in the Republic of Ireland, third largest on the island of Ireland, the county town of County Cork and largest city in the province of Munster. The city centre is an island between two channels of the River Lee which meet downstream at its eastern end, where the quays and docks along the river lead outwards towards Lough Mahon and Cork Harbour, one of the largest natural harbours in the world.
Cork was founded in the 6th century as a monastic settlement, and was expanded by Viking invaders around 915. Its charter was granted by Prince John in 1185. Cork city was once fully walled, and the remnants of the old medieval town centre can be found around South and North Main streets. The city's cognomen of "the rebel city" originates in its support for the Yorkist cause in the Wars of the Roses. Corkonians refer to the city as "the real capital", a reference to its opposition to the Anglo-Irish Treaty in the Irish Civil War.