There are some doubts as to the meaning of the name of Oslo. Researchers agree that the term Os can be understood as either a long and narrow hill or as a reference to a pre-Christian God. The second half of the name, Lo, generally refers to a field. Hence the ancient name of Oslo may either mean the field below the hill or the field of the Gods.

By 1300 when the construction of the Akershus fortress and castle was started, the city was already an important trade centre. As most of the buildings were of a wooden construction with turf roofs, the city was plagued by fires. After the great fire that destroyed the city in 1624, the Danish King Christian IV, decided to rebuild the city in brick and stone, and named it Christiania.

In the area known as Kvadraturen, some of the buildings dating from the 17th century have been preserved. At the beginning of the 19th century, the city was the size of a small town, but with the mid-19th century economic surge, Oslos population began to grow rapidly and people migrated to the capital from all over Norway in search of employment. In the period from 1850 to 1900, the population increased from a mere 30 000 to 220 000 inhabitants.

Since the separation from Sweden in 1905, national awareness increased, and this sentiment lead to a Parliamentary Decree renaming the city Oslo in 1925. In 1948, the two municipalities of Oslo and Aker merged, increasing the area of Oslo to 454 km2 and the population by approximately 135 000 inhabitants. In the 1950s, in order to accommodate the increasing population, the suburbs were developed through large-scale building projects. At the same time the public transport system was expanded, facilitating the transfer from the suburbs to the city centre. One of the most recently developed areas of the city is Aker Brygge.

Once a ship's wharf, it is today a symbol of the modern Oslo: a pedestrian area with lots of shops, restaurants and cultural activities - all in close proximity to the fjord - just like the first settlements more than 1000 years ago.

Over the next few years, Oslo will undergo some of the most significant changes for decades. The entire dockside area will be developed and made accessible to the city's inhabitants and visitors. The development will include new housing, commercial areas, museums, recreational areas, cultural buildings and a new exciting opera building. The new Opera House will be the largest cultural building ever to be erected in Oslo, and will be a magnificent sight for those arriving in Oslo by sea.

The Fjord City is the name of the project where the Oslo City Council will reclaim the land next to the sea and develop it in such a way that it will open the fjord to the city. A large area of land which is used today for shipping and cargo will be developed for other purposes, bringing the fjord closer to the city and opening it up to the benefit of Oslo's inhabitants and visitors.

The project was started in 2003, and the first part of the project, including the new Opera House, is expected to be completed in 2008.