Akershus Fortress (Akershus Festning) or Akershus Castle (Akershus slott) is a medieval castle that was built to protect Oslo, the capital of Norway. It has also been used as a prison.
The first construction on the castle started around the late 1290s, by King Haakon V, replacing Tønsberg as one of the two most important Norwegian castles of the period. It was constructed in response to the Norwegian nobleman, Earl Alv Erlingsson of Sarpsborg ’s earlier attack on Oslo. The fortress has successfully survived all sieges, primarily by Swedish forces. In the early 17th c., the fortress was modernized and remodelled under the reign of the active King Christian IV, and got the appearance of a renaissance castle. The fortress was first used in battle in 1308, when it was besieged by the Swedish duke Eric of Södermanland.
The immediate proximity of the sea was a key feature, for naval power was a vital military force as the majority of Norwegian commerce in that period was by sea. The fortress was strategically important for the capital, and therefore, Norway as well. Whoever ruled Akershus fortress ruled Norway. The fortress has never been successfully captured by a foreign enemy. It surrendered without combat to Nazi Germany in 1940 when the Norwegian government evacuated the capital in the face of the unprovoked German assault on Denmark and Norway.
Akershus has also been a prison, a section of it known as The Slavery (Slaveriet) as the prisoners could be rented out for work in the city. It has housed many rebels and criminals through Norwegian history. Particularly well-known people to have been imprisoned there includes the semi-legendary " thief of the people " and author Gjest Baardsen, and the similarly idealized thief Ole Høiland. Also, many early Norwegian socialists also spent time in the cells of Akershus. Following the 1852 Laestadian Sámi revolt in Guovdageaidnu, all men except the two leaders Aslak Hætta and Mons Somby ended up in Akershus Fortress – the women were imprisoned in Trondheim. Many of the rebels died after a few years in captivity.
Akershus fortress is still a military area, but is open to the public daily until 9pm. In addition to the castle, the Norwegian Armed Forces Museum and the Norwegian Resistance Museum can be visited there. The Norwegian Ministry of Defence and Defence Staff Norway have a joint modern headquarters in the eastern part of Akershus Fortress.
Norwegian Royalty have been buried in the Royal Mausoleum in the castle. They include King Sigurd I, King Haakon V, Queen Eufemia, King Haakon VII, Queen Maud, King Olav V and Crown Princess Märtha. A portion of the fortress was replicated at the Norway pavilion at Epcot Center theme park in Orlando, Florida.