Oslo is a municipality, as well as the capital and most populous city in Norway. As a municipality (formannskapsdistrikt), it was established on 1 January 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 Castle, as Christiania (also spelled Kristiania in late 1800s). In 1925, the city reclaimed its original Norwegian name, Oslo. The diocese of Oslo is one of the five original dioceses in Norway, which originated around the year 1070.
Oslo is the cultural, scientific, economic and governmental centre of Norway. The city is also a hub of Norwegian trade, banking, industry and shipping. It is an important centre for maritime industries and maritime trade in Europe. The city is home to many companies within the maritime sector, some of which are amongst the world's largest shipping companies, shipbrokers and maritime insurance brokers. Oslo is a pilot city of the Council of Europe and the European Commission intercultural cities programme.
Oslo is considered a global city and ranked "Beta World City" in studies performed by the Globalization and World Cities Study Group and Network in 2008. For several years, Oslo has been listed as one of the most expensive cities in the world along with such other global cities, as Zurich, Geneva, Copenhagen, Paris, and Tokyo. In 2009, however, Oslo regained its status as the world's most expensive city. A survey conducted by ECA International in 2011 placed Oslo 2nd after Tokyo.
As of 2010, the metropolitan area of Oslo has a population of 1,442,318 of whom 912,046 live in the contiguous conurbation. The population currently increases at a record rate of 1.64% annually, making it the fastest growing city in Europe. This growth stems from immigration, as the Norwegian population in the city is decreasing. The immigrant share of the population in the city proper now counts more than 25% of the city's total.
Oslo is one of very few cities in Norway, besides Bergen and Tønsberg, that does not have a formal coat-of-arms, but which uses a city seal instead. The seal of Oslo shows the city's patron saint, St. Hallvard, with his attributes, the millstone and arrows, with a naked woman at his feet. He is seated on a throne with lion decorations, which at the time was also commonly used by the Norwegian Kings.
Oslo has a humid continental climate (Dfb according to the Köppen climate classification system). Because of the city's northern latitude, daylight varies greatly, from more than 18 hours in midsummer, when it never gets completely dark at night, to around 6 hours in midwinter. Despite its northerly location, the climate is relatively mild throughout the year because of the Gulf Stream.
Oslo is a compact city. It is easy to move around by public transportation and you can access rentable city bikes all over the city centre. In 2003, Oslo received The European Sustainable City Award and in 2007 Reader's Digest ranked Oslo as number two on a list of the world's greenest, most liveable cities.
