The Archdiocese of Nidaros was the metropolitan see covering Norway in the later Middle Ages. The see was the Nidaros Cathedral, in the city of Nidaros. The archdiocese existed from the middle of the

Nidaros, Niðarós or Niðaróss was the medieval name of Trondheim when it was the capital of Norway's first Christian kings. It was named for its position at the mouth of the River Nid.