In 1152 Norway became a separate diocese in the Catholic world system. This also led to the establishment of a Norwegian archbishop’s seat in Nidaros [now Trondheim]. Not much is known about the first archbishop, Jon Birgersson. But his successor, Archbishop Eystein, has left clear traces after him.
Eystein Erlendsson was from Trøndelag, probably born just before 1130. On his mother's side he descended from Erling Skjalgsson. Eystein appears to have been a learned man, and this suggests that he must have been studying abroad in his youth. Later he entered the inner circle around King Inge Krokrygg [the Hunchback] as a chaplain. When Jon died (probably in 1157), Erlend was chosen as the new Archbishop. It appears that he was not confirmed in this position until 1161.
This was a time of tension between royal power and the church. There were also several contenders for the royal hegemony. In this conflict Eystein sided with Erling Skakke and his son Magnus. When Sverre Sigurdsson eventually gained control over large regions of the realm Eystein was forced into exile. He stayed in Suffolk in England for around three years before returning to Norway in the summer of 1183.
On the political level the archbishop was forced to agree to several compromises, which included coming to terms with King Sverre (whom he had excommunicated). From his final years, history knows Eystein best as the grand strategist during the initial great period of building Nidaros Cathedral. He had brought ideas from England about the new Gothic style, and he let this style dominate the further plans for the Cathedral.
Eystein also left a lasting mark in the form of Passio Olavi, a collection of legends relating to Saint Olav.
Eystein died in 1188. He was proclaimed a saint in 1229, but papal approbation was not forthcoming. Eystein Erlendsson has nevertheless been accepted as a Norwegian saint – one of four. In the new year of 2001 St. Eystein was finally approved by the Vatican, and he is now entered in the register of saints and the beatified. While this is admittedly a modest rank, he is the only Trønder in this famous context. St. Eystein is commemorated on the date of his death, 26 January.