The capital and largest city of Norway, in the southeast part of the country at the head of the Oslo Fjord, a deep inlet of the Skagerrak. Founded c. 1050, Oslo was rebuilt and renamed in 1624 by Christian IV (1577-1648; reigned 1588-1648). It has been the capital of the country since 1299. The Winter Olympics were held here in 1952. Population: 549,000.