Oslo (äzˈlō, äsˈ–, Nor. ŏsˈlŏ) [key], city (1995 pop. 482,555), capital of Norway, of Akershus co., and of Oslo co. (175 sq mi/453 sq km), SE Norway, at the head of the Oslofjord (a deep inlet of the Skagerrak). Oslo is Norway's largest city, its main port, and its chief commercial, industrial, communication, and transportation center. Manufactures include processed food, textiles, forest products, and machinery. It has significant electrotechnical, graphics, and printing industries.
Founded c.1050 by Harold III, Oslo became (1299) the national capital. In the 14th cent. it came under the dominance of the Hanseatic League. After a great fire (1624), the city was rebuilt by Christian IV and was renamed Christiania (later Kristiania); in 1925 the name Oslo again became official. The city's modern growth dates from the late 19th cent., when it also replaced Bergen as the main city in Norway. In World War II, Oslo fell (Apr. 9, 1940) to the Germans, and it was occupied until the surrender (May, 1945) of the German forces in Norway. The neighboring industrial commune of Aker was incorporated into Oslo in 1948.
Today, Oslo is a modern city in design and construction, and its government has fostered contemporary art in a number of impressive public projects. Among these are the 150 sculptural groups by Gustav Vigeland in the famous Frogner Park. The city's chief public buildings include the royal palace (1848), the Storting (parliament), and the city hall (1950), which was decorated by many Norwegian artists. Surviving medieval structures include the Akerskirke (12th cent.) and the Akershus fortress (13th cent.), and there are ruins of the Cathedral of St. Hallvard, the first cathedral of Oslo. The Univ. of Oslo (founded 1811), the national theater (1899), the national gallery, the Oslo Opera House (2008), a Nobel Institute, and a college of architecture are among the city's cultural institutions. The Folk Museum has reconstructions of old Norwegian timber houses and of a 12th-century stave church, and the Kon-Tiki Museum has mementos of Thor Heyerdahl's trip (1947) across the Pacific Ocean. The Astrup Fearnley Museet (2012) is a modern-art museum housed in a complex designed by Renzo Piano. The forested hills surrounding Oslo are popular excursion points; the annual Holmenkollen ski meet nearby attracts an international group of skiers. The 1952 Olympic winter games were held at Oslo. Drøbak, further south on the Oslofjord, is a winter port of Oslo and a summer resort.