In 1550, the episcopate of the last
Catholic bishop of Åbo ended. Thereafter Lutheranism prevailed in Finland. The
Reformation in the sixteenth century caused the loss of almost all of Northern Europe from the Catholic Church. In 1582 the remaining Catholics in Finland and elsewhere in Northern Europe were placed under the jurisdiction of a
papal nuncio in
Cologne. The
Congregation de propaganda fide, on its establishment in 1622, took charge of the vast missionary field, which - at its third session - it divided among the nuncio of
Brussels (for the Catholics in Denmark and Norway), the
nuncio at Cologne (much of Northern Germany) and the
nuncio to Poland (Finland, Mecklenburg, and Sweden). In 1688, Finland became part of the
Apostolic Vicariate of the Nordic Missions. In 1783, the
Apostolic Vicariate of Sweden was created out of parts of the Nordic Missions comprising then Finland and Sweden. In 1809, when Finland came under Russian rule, the Catholic jurisdiction passed on to the
Metropolitan Archdiocese of Mohilev (then seated in St. Petersburg). In 1920, the Vatican established the Apostolic Vicariate of Finland which was erected as the Diocese of Helsinki in 1955. ==Episcopal ordinaries==