A tall shape of a tower in a panorama of Old Town in Slupsk is what makes you recognize old Dominican St Jack's Church (at present, a parish church). It is situated to the south of the old town near Pomeranian Dukes' Castle. Beginnings of the Dominican order in Slupsk date back to the 13th century when Gdansk duke Mestwin II ruling the Slupsk area at that time issued a foundation document for this order in 1278, asked by Woyan – the Gdansk Dominican order abbot. In the document, a location and privileges for a future monastery were specified. In 1325, West Pomerania duke Warcislaw XIV raised previous donations for the Dominican order. Instead, the monastery was obliged to firm and keep municipal walls situated right next to the monastery properties in a good condition.

In 1395, the monastery buildings and the church burnt down in a huge fire in the town. In 1450, the first provincial chapter in Pomerania ever took place, it is believed that both the monastery and the church had been already restored. In 1524, due to religious riots, annoyed crowd robbed the church and the monastery and monks scattered. Neglected and abandoned buildings began to fall into ruin. A breakthrough period in the church history came in the beginning of the 17th century when duchess Erdmuta, a wife of West Pomerania duke Jan Fryderyk, decided to rebuild it. The restoration was completed in 1602, on 24th June the church was consecrated and renamed to St John's Church. It had a function of a castle church until the House of Griffins died out.

In this period, another residents of the nearby castle took care of it, bringing many fantastic works of art to its interior: duchess Erdmuta, duchess Anna de Croy, and the last one of the House of Griffins – Anna's son – duke Ernest Boguslaw Croy who died in 1684. After 1693, the church became a property of the Protestant commune, in 1777 the church tower was rebuilt, two years later the entire building got a new roof. After a fire in 1892, new timber roof trusses were put, the roof was raised (in comparison with its original state), the tower was covered with a Baroque spire. During the Second World War, the warfare did not touch the building, only windows and the roof were partly damaged. After an overhaul in 1946, the church was consecrated again and was renamed to St Jack's Church. It became an independent parish church finally in 1981.

A Renaissance altar with a clear and harmonious construction comes from the beginning of the XVII century. It is decorated with sculptural ornaments and paintings. A picture in the finial shows “The Resurrection”, in another one in the predella you can see “The Last Supper”, and a particularly interesting painting presenting duke Jan Fryderyk with his wife Erdmuta is located in the altarpiece. An author of this work is named Funke that came from Kolobrzeg. The church pulpit also came from the Renaissance. It is richly decorated with paintings and sculptural details. The pulpit body is supported by a figure of Moses and is decorated with images of Evangelists.

On the northern wall of the church you can find richly decorated duchess Anna's marble epitaph – a rectangular plate describing her as the last but one member of the dying family. On the sides of the plate, you can see characteristic, spiral columns and in the epitaph finial there is a figure of Anna giving out alms in a sitting position. Underneath the board you find a figure of Anna in a laying position. On the sides, there is some kind of sculpted projections with Anna and Ernest de Croy's portraits. To the right of the altar, you can see a Baroque gravestone of duke Ernest Boguslaw. A figure of the duke in a kneeling position is situated under the arcade supported by the heads of the titans who hold coats of arms of the Griffins and Croy families. Architectonic elements of the gravestone were made from black marble and the sculptural ones – from white marble. In the background, you can see three tondi with inscriptions, the arcade is crowned with a cartouche with the Croy family's coat of arms. The whole object is surrounded with wrought grating. The gravestone was designed and possibly made by famous Gdansk sculptor – Hans Caspar Gockheller. Probably, duchess Anna's epitaph also came from his workshop.

Duke Ernest Boguslaw is also the one who gave organ to the church. The organ came from the same period as the aforementioned works of grave art. You can recognize them by its richly sculpted front where the Croy and Griffins families' coats of arms are visible. The organ are used for concerts that are organised every summer. An important historic object of the church interior are tombstones from the 17th/18th century and the church consecration plate coming from 1602. For years, the church played a role of a burial place for noble people in the history of West Pomerania. Those who were buried there include duchess Maria (died in 1454), a wife of duke Boguslaw IX, duchess Zofia (died in 1497), a mother of duke Boguslaw X. Bodies of duchess Anna and her son, Ernest Boguslaw, were put in one of the crypts under the altar. Tin sarcophagi having wooden coffins inside, richly decorated with images of cut flowers and a series of coats of arms were made by famous Gdansk craftsman – Gieseler. The sarcophagi were found in 1976 and since their restoration they have been presented as a regular exhibition in the Middle Pomerania Museum.