For other meanings see Nidaros (other meanings) Nidaros is a historical name for the city of Trondheim, as well as the name of the Catholic diocese and archdiocese before 1537, and the Lutheran diocese since. It was first and foremost the shrine of the saint king St. Olav in Nidaros Cathedral that gave the city its central position in Norway and Northern Europe until the Reformation in 1537.
According to Heimskringla, Trondheim was founded by Olav Tryggvason (assumed in 997):
King Olav led his army out to Nidaros. Then he had a house built there on the banks of the Nidelven and decided that there should be a market town there. He gave the men plots to set up houses, and he had the royal estate built up from Skipakrok.
With the establishment of the Archdiocese of Nidaros in 1154, the city's name was Latinized to Trundum (dat. Flt. Meaning the eight Trøndelag counties), the genitive form Nidaros Trundensis Nidaros of the Trønder counties in the Vatican. By Eirik Ivarsson from 1192, the city is called Nidaros both in Nidaros, Norway and in Rome. The Nidaros name of the city later disappeared for several reasons, primarily because the archbishopric disappeared in 1537, but is known to have been used until the 17th and 17th centuries.
Trondheim (en) was originally the name of the eight counties of Trøndelag, ie today's Trøndelag. In the late Middle Ages, Kaupangen in Trondheim, ie the trading post in Trøndelag, was also used as a city name and the short form Trondheim was used in parallel with Nidaros. During the union with Denmark, this was pre-danced to Trondhjem and Trondhjem County for Trondheim County.
In the period 1925–1930, several city names were Norwegianized as part of the linguistic nationalism that was widespread in Norway in the first part of the 20th century (1925: Oslo, 1927: Halden, 1930: Stavern). By law of 14 June 1929, it was decided that the city of Trondheim from 1 January 1930 should have Nidaros as its official name. Earlier, in 1928, a local referendum was held on the city name: 17,163 voted against the change, and 1508 in favor. The population and the city council, who wanted to keep Trondhjem as their name, felt overwhelmed and the protests did not wait.
After a harrowing name dispute, the matter was taken up again in the Storting. This ended in a compromise: by law of 6 March 1931 with effect from the same day, the form Trondheim was introduced, a "Norwegianized" alternative launched by Ivar Lykke, local merchant, prime minister 1926-28 and parliamentary representative 1915-35.