The Cathedral of the Immaculate Conception of the Blessed Virgin Mary in Siedlce is one of many neo-Gothic churches that were built in Poland. The activities undertaken to build it, starting in 1854, took a very long time and ended only in 1901 with obtaining official permission. In 1902, Zygmunt Zdański developed a design and estimated the cost of the future church. Work began in the fall of 1900, and most of it was completed in 1912. The Cathedral of the Immaculate Conception was built according to a tile-head pattern on a Latin cross plan, which was typical of medieval architecture. It is a pseudo-hall church, with three naves, with a transept and an elongated choir, closed on three sides. On both sides of the choir there are two rectangular chapels opening onto the transept. Behind the chapels there are two sacristies, one for bishops and the other for canons. The pediment is topped at the base with two square towers. The building is covered with a gable roof. The period in which the work was carried out was particularly difficult. From 1867, Siedlce became the seat of the Russian Governor General and came under the strict control of the partitioning powers. The tsar's government sought to eradicate all national feelings and all manifestations of Polish culture and consciousness. However, the architecture of this period was, among other things, an expression of resistance to these goals.