Trondheim (Norwegian pronunciation: [ˈtrɔnhæɪm]), historically Kaupangen, Nidaros and Trondhjem, is a city and municipality in Sør-Trøndelag county, Norway. With a population of 181,513 (October 1, 2013), it is the third most populous municipality in Norway, although the fourth largest urban area. It is also the third largest city in the country, with a population (2013) of 169,972 inhabitants within the city borders.[2] The city functions as the administrative centre of Sør-Trøndelag county. Trondheim lies on the south shore of the Trondheimsfjord at the mouth of the river Nidelva. The city is dominated by the Norwegian University of Science and Technology (NTNU), SINTEF, St. Olavs University Hospital and other technology-oriented institutions.

The settlement was founded in 997 as a trading post, and it served as the capital of Norway during the Viking Age until 1217. From 1152 to 1537, the city was the seat of the Archdiocese of Nidaros; since then, it has remained the seat of the Diocese of Nidaros and the Nidaros Cathedral. It was incorporated in 1838. The current municipality dates from 1964, when Trondheim merged with Byneset, Leinstrand, Strinda and Tiller.