WARMIA (ERMLAND), DIOCESE OF. - City and diocese in East Prussia, today in Poland. It has an area of 23,344 sq km with a population of 749,401 inhabitants, of whom 684,494 are Catholics, distributed in 216 parishes, served by 175 diocesan priests and 59 regulars; it has two seminaries, 8 male religious communities and 50 female ones (Ann. Pont. 1953, p. 452).
The diocese is a suffragan of Breslau; it was created by Innocent IV on 30 July 1243, directly subject to the Holy See. The episcopal residence was at Heilsberg until around 1800, while the Chapter resided first at Braunsberg and from 1288 at Frauenburg. With the Peace Treaty of Thorn (1466) W. passed from the dominion of the Teutonic Order of the Crutched Friars to that of Poland; indeed in 1512 King Sigismund, with the Treaty of Parezow, secured for himself the predominant influence in the election of the bishop. The diocese suffered because of Protestantism, the Swedish wars (1626-1709) and the Napoleonic campaign of 1807, after Prussia had annexed its territory from 1772; further destruction occurred in the war of 1915-18; by the Treaty of Versailles Danzig was detached from W., which in 1926 also lost the parishes of the Memel territory; by the Concordat of 14 June 1929 W. became a suffragan of Breslau; since 1945 it has had an apostolic administrator.
The first bishop of the diocese was Andrew (c. 1245-65). In 1457 Card. E. Silvio Piccolomini was elected, but he did not take possession of the see. Nicolaus Copernicus (v.), b. at Frauenburg in 1543, was for some time administrator of the diocese. The bishop Stanislaus Hosius (v.) was distinguished, having been transferred to W. from the see of Kulm and made a cardinal in 1560; he was one of the pontifical legates at the Council of Trent, author of the Confessio fidei catholicae christianae which had an enormous diffusion; he struggled strenuously against the Lutheran menace in his diocese; he founded in Rome (1578) the church of S. Stanislao alle Botteghe Oscure; he is buried in Rome at S. Maria in Trastevere. He was succeeded by Martin Kromer (1579-89); Card. A. Batori (d. 1599); Card. John Albert (1621), son of King Sigismund.
The Cathedral is from 1350. In 1565 the Jesuit College was erected, to which were annexed the diocesan seminary (1567) and the « Liceum Hosianum » (1578); a second Jesuit college was established at Rösseil in 1632.