Nidaros Cathedral

Olav II of Norway, who brought Christianity to the country and became its patron saint, was killed at the Battle of Stiklestad in 1030 and buried at Nidaros, the old name for Trondheim, taken from the mouth of the river Nid. A year after his death Grimketel, the Bishop of Nidaros, canonised him, and the papacy confirmed the canonisation later. After Stiklestad he was recognised as a martyr, one who had died for his Christian faith. A spring of holy water was said to have risen where the king lay through that first winter, and popular belief credited it with healing powers; by tradition it fed the well that stands in the church today. Pilgrims travelled from across Europe to reach the grave and the water of Olav's well, and in the Middle Ages Nidaros was the most important pilgrimage destination in the Nordic countries; the church was in large part built to receive them.

A small wooden chapel was raised in about 1035. Around 1070 King Olav III Kyrre, St Olav's nephew, began a large stone church on the site where a wooden church had stood. It was dedicated to the Holy Trinity but was commonly called Kristkirken, an older word for a cathedral, and its altar was set over the grave; when the building was finished around 1090 the saint's shrine was moved in above that altar. Kristkirken ran to some fifty metres and was the largest church in Norway at the time. Almost all the Norwegian royals of the eleventh and twelfth centuries were buried in it.

In 1152 Norway became a church province in its own right and Nidaros was made the seat of an archbishop, the pope's aim being a firmer hold on northern Europe. The standing of St Olav had already made the town a centre of power; Norwegian kings were crowned there, and towards the end of the eleventh century Adam of Bremen had described Nidaros as Norway's metropolis civitas, its capital. Kristkirken was now too small, both for the pilgrims arriving and for the rank the church had acquired, and the first two archbishops, Jon and Øystein, set a large building programme in motion to enlarge it. The old church served as the choir while the new transept went up in an Anglo-Norman Romanesque manner.

Archbishop Øystein spent a period in exile in England during the succession dispute with King Sverre. He returned in 1183, and the work was turned to the early Gothic then usual in English cathedrals. A larger choir was raised around the old Kristkirken, which was afterwards pulled down. The octagon at the east end, with its surrounding ambulatory, was also built in Øystein's time, and the silver shrine of St Olav was placed on the high altar within it. Many of the masons were foreigners, Englishmen above all, and the choir appears to have been modelled on the Angel Choir at Lincoln.

The nave was the last part to be finished. The foundation stone of the west front was laid in 1248, and the Gothic nave was built in basilica form in roughly 1250 to 1300. The cathedral is reckoned substantially complete in 1300 by some accounts and around 1320 by others, and additions and renovation have gone on intermittently ever since.

Fire took the cathedral in 1327, in 1432, probably in 1451, and again in 1531. The Reformation reached Norway in 1537, shortly after the last of those fires. The archdiocese was abolished, the Catholic church lost the greater part of its landed estates, and the building has served since as a Lutheran church, seat of the bishops of Trondheim, or Nidaros, in the Diocese of Nidaros. For the centuries that followed there was money for little beyond necessary upkeep. The nave lay in ruins and was shut off from the rest of the church by a wall, and it was not rebuilt until the restoration of the early twentieth century. In 1708 the whole cathedral burned but for its stone walls, and lightning set it alight once more in 1719.

The silver-gilt reliquary casket that had held the saint's remains was melted down for coinage by Christian II, and the remains themselves were buried under the cathedral in a place that is not known. The only relic known to have survived is a femur, kept in a silver-gilt reliquary shaped as a forearm, which Queen Josephine gave to St Olav Catholic Cathedral in Oslo.

In 1814 the cathedral served as an election church. With more than three hundred other parish churches across Norway it was a polling station in the country's first national elections, held to choose the Constituent Assembly that met at Eidsvoll and wrote the Constitution. It was the only building named in the Constitution of 1814: the men at Eidsvoll laid down that the regent of Norway should be crowned in Trondheim.

That decision drew the authorities' attention to how far the fabric had decayed, and a large rebuilding began in 1869, led at first by the architect Heinrich Ernst Schirmer and carried nearly to completion by Christian Christie. Only the eastern parts were meant to be restored to begin with; rebuilding the nave, of which just the lowest courses of wall still stood, was judged too great an undertaking. After the dissolution of the union with Sweden in 1905 the Storting decided that an independent Norway should have a complete cathedral, and the rebuilding was officially finished in 2001. Maintenance of the building is a continuing task.

The cathedral was last used for a coronation in 1906, when King Haakon VII was crowned. Since the coronation ceremony was abolished it has been used for the consecration of the regent, and new Norwegian monarchs are consecrated there still. The Norwegian crown regalia are displayed in the Riksregaliemuseet, in the Lavetthuset of the Archbishop's Palace beside the cathedral.

Several thousand pilgrims a year still reach the cathedral along the historic Pilegrimsleden, travelling to pay homage to St Olav, at whose tomb Christian tradition holds that miracles occurred. On arrival they traditionally walk around the building three times before entering, and they complete the pilgrimage by attending Mass and receiving the Eucharist, after which the cathedral grants them a pilgrim certificate. Mass and the Divine Office in the Evangelical-Lutheran tradition are celebrated daily. The cathedral is also the setting for Olavsvaka, the festival held on the anniversary of Olav's death at Stiklestad.

The altar in the crossing carries a large silver crucifix commissioned and paid for by Norwegian American emigrants in the early twentieth century, its design taken from the memory of a similar crucifix in the medieval church. Of the two organs, the older was built by the German organ builder Joachim Wagner in the late 1730s and erected by the journeyman Peter Migend in 1741; Jürgen Ahrend restored it in the 1990s. The main organ was ordered from the Steinmeyer firm for the nine hundredth anniversary of the Battle of Stiklestad in 1930 and paid for mostly by donations, in particular by Elias Anton Cappelen Smith. It was heavily rebuilt and moved to the west end in 1962, and restored in 2014.

It was rumoured that members of the Norwegian band Mayhem, whose 1994 album De Mysteriis Dom Sathanas carries the cathedral on its cover and who were already associated with the burning of other Christian churches in Norway, had planned to destroy it; when police arrested the group's former bassist Varg Vikernes on 19 August 1993 they found 150 kilograms of explosives at his home. Today the cathedral is the main church of the Nidaros og Vår Frue parish, the seat of the Nidaros domprosti or arch-deanery and of the Bishop of the Diocese of Nidaros, and the base of the Preses of the Church of Norway. It seats about 1,850 people and is protected under Norwegian cultural heritage preservation. It is the largest church in Norway and the second largest Gothic church in the Nordic countries after Uppsala Cathedral, and it is the northernmost medieval cathedral in the world.