The present church was built in the fifteenth century in the place of the earlier of the thirteenth century, which was destroyed in 1415 as a result of a fire. The reconstruction of the temple was prolonged due to lack of funds. In 1444, the new sacristy was mentioned, in 1447 a new presbytery, and in 1470 funds were collected for renovation works in the church, defined as damaged. At that time, it was erected, partly based on the walls of the earlier building, the church’s hall, along with the lower parts of the towers. At the turn of the 15th and 16th centuries, annexes were built on the sides of the church hall, including the chapel of the Holy Trinity (so-called Piastowska) mentioned in 1518 and chapels of St. Jadwiga and St. Anne. The final completion of the church’s reconstruction took place in 1520 during the reign of prince Jan II the Good.
Subsequent repairs were mentioned in 1555 and 1557. Perhaps at that time the old vault was replaced with a new one. During the fire of the city in 1615, the roof, the gable and one of the towers, as well as most of the interior decoration were destroyed. In 1617 the renewal of the church was completed, but in the years 1622 and 1647 further damages occurred as a result of fires. In 1652, the roof was rebuilt, and in 1653 the vaults were renovated. In the second half of the seventeenth century, a new sacristy was erected. In 1724, the shingle roof was replaced with a tile roof. After secularization carried out in 1810, the collegiate established in the 13th century, ceased to exist. In the nineteenth century, subsequent renovations were carried out: the vaults were strengthened, the buttresses were renovated and interiors were renewed in the neo-gothic style. In the years 1897-1902, external elevations were changed, some windows were walled, the outbuildings were unified and the western façade was erected with the towers superstructure according to the design of architect Józef Cimbollek. At that time, the southern porch was also extended by one span. In the years 1912-1914 a music choir was built into the western span of the body, and a staircase was added to the northern tower. During the renovation in 1960, neogothic changes made in the 19th century were largely removed.
The gothic cathedral was built of brick in the monk bond. After the 15th century reconstruction, the former basilica church was replaced with a hall temple. It consists of a three-nave, five-span corpus without a separate chancel, with three-side ending from the east. Two towers are added from the west. From the south adjoins the two-span chapel called Piasts and two sacristies, while from the north are added chapels of St. Jadwiga and the chapel of St. Anne. The church from the outside is closed with buttresses, between which there are pointed windows. The nave covers the common gable roof.
Inside, the central nave is covered with a net vault, while the aisles are covered with net-stellar vaults from the mid-sixteenth century, supported by pointed arcades and octagonal pillars. The Piasts Chapel is covered with a rib vault, the chapel of St. Jadwiga with a stellar vault, while the chapel of St. Anna with a barrel-rib vault from around 1635.
Kozaczewska H., Średniowieczne kościoły halowe na Śląsku, “Kwartalnik Architektury i Urbanistyki”, 1-4, Warszawa 2013.
Pilch J, Leksykon zabytków architektury Górnego Śląska, Warszawa 2008.
Website wikipedia.org, Kościół katedralny Świętego Krzyża w Opolu.