1040 – The city was founded by King Harald Hardrada, initially called "Ánslo".
1050 – Believed to be the year the city was officially founded, although historical records are ambiguous.
1300 – Construction of the Akershus Fortress started under King Haakon V.
Early Modern Period
1624 – A great fire destroyed much of the city. King Christian IV of Denmark-Norway rebuilt the city near Akershus Fortress and changed its name to "Christiania".
1814 – Christiania served as a temporary capital of the independent Kingdom of Norway during the Napoleonic Wars.
19th Century Development
1850 – Christiania overtook Bergen to become the most populous city in Norway.
1878 – The University of Oslo's new main building was completed, signifying the city's growing importance as a seat of learning.
1894 – The Norwegian Parliament, the Storting, constructed a new building, emphasizing the city's role as the political center of Norway.
20th Century Transformation
1905 – Christiania became the de jure capital of an independent Norway, following the dissolution of the union with Sweden.
1925 – The city's name was officially changed back to "Oslo".
1940-1945 – Oslo was occupied by German forces during World War II.
1952 – The city hosted the VI Winter Olympic Games.
1960s – The post-war expansion led to significant urban development, reflecting its economic growth.
21st Century Milestones
2000 – Oslo's celebrated new opera house opened, garnering international acclaim for its architecture and acoustics.
2011 – The city experienced a tragic terror attack, with a bomb exploding in the government quarter.
Modern Developments
2021 – The MUNCH museum, dedicated to the life and work of the artist Edvard Munch, opened in a new waterfront building.
2022 – Oslo completed several environmentally friendly urban development projects as part of its commitment to sustainability and being named European Green Capital in 2019.