(AUGUSTÓWO; SEJNESIS, or AUGUSTOVIENSIS).
A diocese in the northwestern part of Russian Poland near the border of East Prussia, of Russian Poland near the border of East Prussia, German Poland. Its territory formerly belonged to the Diocese of Vilna, but upon the first partition of Poland it fell to Germany. Consequently a separate ecclesiastical jurisdiction was desired, and so Pius VI, on 27 March, 1798, carved out the new diocese and established its see at the Camaldolese monastery of Wigry, a village about ten miles east of the present city of Suwalki. This monastery of Camaldoli was founded under the patronage of King Jagiello in 1418, and the Church of Our Lady, which became the cathedral, is now the parish church of Wigry. The first bishop of the diocese was the celebrated preacher Michael Francis Karpowicz (b. 1744; d. 1805). His successor was John Clement Golaszewski (b. 1748; d. 1820), who enlarged the Wigry cathedral. After the third partition of Poland this territory was ceded to Russia, and in 1818 the Church throughout the Polish kingdom was reorganized. By a Bull of Pius VII Warsaw was made the metropolitan see and the see of Wigry was changed to Augustówo, a city founded in 1561 by King Sigmund Augustus, after who, it was named, which is still the largest place in that section (population 65,690). The new cathedral and chapter there were inaugurated on December 8, 1819. The next bishop, Ignatius Czyzewski, the first to rule the newly named diocese, did not remain at Augustówo, but changed his place of residence in 1823 to Sejny, a town founded in 1522 by King Sigmund I, and which is about twenty miles east of Suwalki, the capital of the district. The succeeding bishop, Nicholas John Manugiewicz, established the diocesan seminary in 1830, and for many years resided sometimes at Augustówo and then at Sejny. His successor was Stanislaus Choromanski, afterwards Archbishop of Warsaw. Then next bishop, Straszynski, made the old Dominican church at Sejny his cathedral and entered it as bishop, 4 February, 1837. He was in frequent collision with the Russian authorities, and on his death in 1847 the see was kept vacant by the Russian Government until 1873. Constantine Lubienski was then made bishop, and on his death in 1869 at Nowgrodzie was succeeded by Bishop Wierbowski. His successor was Anthony Baranowdki, and the present bishop (1911) is Anthony Karas. Sejny has the cathedral church, chapter and consistory, the diocesan seminary and the hospital of St. Simon managed by the Sisters of Charity. The diocese is divided into eleven deaneries and has a Catholic population of 692,250. There are 119 parish churches and 20 subordinate ones, besides 100 chapels and 3 convents. The diocese has 352 secular priests, 4 regulars, 86 seminarians, 24 lay religious, besides 8 nuns and 26 Sisters of Charity. Owing to the Russian regulations against receiving novices and postulants, the regular clergy and monastic institutions are dying out.
BATTANDIER, Annuaire Pontificale (Paris, 1911); Slownik Geograficzny, X (Warsaw, 1900).