[2] Additionally, a domed side chapel in the Baroque fashion was erected for the Kings of Poland and Catholic worship in the late 17th century.

With a seating capacity of over 25,000 and a volume of approximately 155,000 cubic metres (5,500,000 cu ft), it is one of the three largest brick churches ever constructed, along with San Petronio in Bologna and the Frauenkirche in Munich.

According to tradition, as early as 1243 a wooden Church of the Assumption existed at this site, built by Swietopelk II, Duke of Pomerania.

In July 1557, King Sigismund II Augustus of Poland granted Gdańsk the religious privilege of celebrating communion with both bread and wine.

[2] As part of the smooth transition Lutheran pastors and services at first also continued Catholic traditions, including using precious liturgical garments, such as chasubles.

[2] In 1594, the Polish royal court tribunal attempted to restore Catholic services to St. Mary's, but the City Council rejected that approach.

[2] It was erected by Tylman van Gameren (Gamerski) and completed in 1681, near St. Mary's Church, for the king's Catholic service when he visited Gdańsk.

With St. Mary's pastor Constantin Schütz (1646–1712) a moderate pietist theology replaced the previously dominant Lutheran orthodoxy.

[2] In the course of the Partitions of Poland the city lost its autonomy in 1793, regaining it for a short period (1807–1814) as a Napoleonic client state, before it became part of the Kingdom of Prussia in 1815.

[2] Gdańsk's then senior, and prime pastor at St. Mary's (1801–1827), Karl Friedrich Theodor Bertling, became a consistorial councillor in the church body.

In 1820, during Bertling's pastorate, long forgotten chests and cabinets in the sacristy were opened and the first medieval garments and liturgical decorations were rediscovered.

[12] So when Chaplain Franz Johann Joseph Bock, art historian and curator of the then Cologne Archdiocesan Museum, reviewed the discoveries he acquired a number of the best pieces from the congregation.

[13] In 1861–64 a Sexton named Hinz systematically searched chests, cabinets and other storages in chambers and rooms, also in the tower, and found many more historic liturgical garments.

[6] In the 1870s and 1880s the congregation sold more than 200 incomplete pieces, but also intact altar cloths and embroideries to the Berlin Museum of Decorative Arts.

[12] The remaining pieces of the garment collection, the so-called Danziger Paramentenschatz (Gdańsk Parament Treasure),[14] mostly originate from the 150 years between 1350 and 1500.

[15] The congregation also sold other artifacts, such as the winged triptych by Jan van Wavere, acquired by Archduke Maximilian, now held in the Church of the Teutonic Order in Vienna, and the sculpture of the Madonna and Child by Michael of Augsburg from the main altar, sold to Count Alfons Sierakowski, now in the chapel in Waplewo Wielkie.

[12] In 1936 the Paramentenschatz was moved to a newly equipped room in the City Museum with a controlled climate, since the Barbara Chapel was too damp.

The presbytery of St. Mary's Church agreed to remove items like archive files and artworks such as altars, paintings, epitaphs, mobile furnishings to places outside the city.

[17] The church was severely damaged late in World War II, during the storming of Gdańsk city by the Red Army in March 1945.

The floor of the church, containing priceless gravestone slabs, was torn apart, allegedly by Soviet soldiers attempting to loot the corpses buried underneath.

[citation needed] By the end of the Second World War many German parishioners of St. Mary's fled westwards, and also the parament treasure was evacuated to the west.

[citation needed] Most of St. Mary's surviving parishioners wound up in the British occupation zone in northern Germany.

[19] Gdańsk was gradually repopulated by more Poles, and Polish authorities handed over St. Mary's Church to the Catholic diocese.

[20] In 2020, the 15th-century Gothic Pietas Domini altar, which was stolen by Germany during World War II, was restored to the church from Berlin.

Similar turrets can be found on the town hall of Lübeck as well as on the two large Churches of Leiden and on the Ridderzaal in The Hague.

The church is stabilized by strong buttresses and has seven portals – one in the west under the steeple, one in the eastern façade of the choir, two on the northern and three on the southern side.