WARMIA (ERMLAND), Diocese of. — A city and diocese in East Prussia, now in Poland. It covers an area of 23,344 sq km with a population of 749,401, of whom 684,494 are Catholics, distributed across 216 parishes served by 175 diocesan priests and 59 religious; it has two seminaries, 8 male and 50 female religious communities (Ann. Pont. 1953, p. 452).
The diocese is a suffragan of Wrocław; it was established by Innocent IV on 30 July 1243, directly subject to the Holy See. The episcopal see was at Heilsberg until around 1800, while the Chapter resided first at Braniewo and from 1288 at Frombork. By the Peace of Thorn (1466), Warmi(a) passed from the rule of the Teutonic Order to that of Poland; indeed, in 1512 King Sigismund secured through the Treaty of Parezow the right to dominate the election of the bishop. The diocese suffered from Protestantism, the Swedish wars (1626–1709), and Napoleon’s campaign of 1807, after which Prussia annexed its territory in 1772; further destruction occurred in the war of 1915–18. By the Treaty of Versailles, Gdańsk was detached from Warmi(a), which in 1926 also lost the parishes in the Memel territory. Under the Concordat of 14 June 1929, Warmi(a) became a suffragan of Wrocław; since 1945 it has had an Apostolic Administrator.
The first bishop of the diocese was Andreas (c. 1245–65). In 1457 Cardinal E. Silvio Piccolomini was elected but never took possession. Nicolaus Copernicus (q.v.), at Frombork in 1543, served for a time as administrator of the diocese. Notable was Bishop Stanislaus Hosius (q.v.), who moved to Warmi(a) from Chełmno and became a cardinal in 1560; he was one of the papal legates at the Council of Trent, author of the *Confessio fidei catholicae christianae*, which enjoyed wide circulation, and a vigorous opponent of Lutheran influence in his diocese; he founded in Rome (1578) the church of S. Stanislao alle Botteghe Oscure and is buried in Rome at S. Maria in Trastevere. He was succeeded by Marcin Kromer (1579–89), Cardinal A. Batory (d. 1599), and Cardinal Jan Albert (1621), son of King Sigismund.
The cathedral dates to 1350. In 1565 the Jesuit College was erected, to which the diocesan seminary (1567) and the Liceum Hosianum (1578) were attached; a second Jesuit college was established at Reszel in 1632.