Oslo is a municipality as well as the capital and most populous city in Norway. As a municipality it was established on January 1 1838. Founded around 1048 by King Harald III of Norway the city was largely destroyed by fire in 1624. The city was moved under the reign of Denmark–Norway's King Christian IV. It was rebuilt closer to Akershus Fortress as Christiania (briefly also spelt Kristiania). In 1925 the city reclaimed its original Norwegian name Oslo.