St. Olav’s Shrine was the resting place of the earthly remains of St. Olav, Norway’s patron saint, behind the high altar of Nidaros Cathedral in Trondheim, Norway, from the mid 11th century. For nearly five centuries the shrine was of major religious importance to Norway and the other Nordic countries, and also to other parts of Northern Europe. St. Olav’s Shrine opens and closes the Middle Ages as a historic period in Norway. The shrine consisted of three shrines, the one covering the other, and was the most important and by far the most valuable object in Norway in the Middle Ages. After the Lutheran reformation in 1536–1537, the valuable parts of St. Olav’s Shrine were destroyed by Danish authorities. Since 1568 St. Olav’s earthly remains have been resting in an unknown grave, in Nidaros Cathedral or in the cathedral cemetery.