The first reference to the church comes from 1272 and is placed on the document of bishop Thomas II, which defines the size of the archiprezbiteriats of Krosno and Żagań. The construction of the original church, which was then a parish church, probably began shortly after the location of the town, which took place between 1248 and 1260. In 1284, the duke of Głogów, Przemko, brought Augustinian canons from Nowgoród, who received the church along with the function of the clergy. After 1333 they extended the original building with a gothic chancel, and in the second half of the fourteenth century they transformed its basilica shape into a three-nave hall with a tower. After the damages caused by the fires in 1472 and 1486, the church was rebuilt, covering the interiors with vaults, and in 1602 the west elevation was enriched with a gallery with a loggia. After a fire in 1730, the rebuilt interior received a rich, baroque décor. Unfortunately, the shape of windows and the roofs over the naves and the tower were also transformed. In the nineteenth and twentieth centuries, numerous renovations of the church were carried out, the largest in the years 1848-1853, 1946 and 1983-1988.
The original church from the 13th century was probably a three-nave basilica, that is a building with a central nave above the aisles and illuminated by windows placed in the clerestorium. Reconstruction from the first half of the fourteenth century enriched the church structure with a gothic, narrower chancel with an east end in the form of a straight wall. In the second half of the fourteenth century, the basilica shape of the temple was transformed into a hall, raising the height of the side aisles. A massive, four-sided, richly ornamented with blendes tower was erected at the southern facade. The last medieval changes took place in the fifteenth century, when the naves were extended towards the west, the central nave was raised and the vaults were placed inside the church.
Pilch.J, Kowalski S., Leksykon zabytków Pomorza Zachodniego i ziemi lubuskiej, Warszawa 2012.
Website lwkz.pl, Żagań – kościół parafialny pw. Wniebowzięcia NMP.
Website wikipedia.org, Kościół Wniebowzięcia Najświętszej Maryi Panny w Żaganiu.