This single nave Romanesque temple was built by the Johannites at the turn of the 13th century. (The Johannites were an order of knights established at the time of the Crusades to fight the Muslims and look after sick pilgrims. When the Crusades were over, they built monasteries all over Europe. Until the times of Napoleon Bonaparte their headquarters were on the island of Malta and for that reason they were often called the Maltese Knights.) At the turn of the 16th century the church was enlarged gaining some late Gothic elements. That was when the side nave was added, the ceiling over the main nave was raised and the spire erected (completed in 1512). In 1736 the Baroque Chapel of the Holy Cross, commissioned by the Johannites Commander, Michał Dąbrowski, was built.
The church is most probably the oldest brick temple in Poland. In the west facade there is a portal with stone Romanesque elements. The right column was reconstructed in 1948. The interior has Gothic stellar vaulting and the chapel is capped with a cupola. The interior polychromy was made in 1948 by Stanisław Teisseyre, who also designed the stained glass window in the chancel made by Stanisław Powalisz. The high altar features a painted Gothic triptych from the early 16th century. At its centre there are images of Our Lady with the Infant, John the Baptist and St Stanislaus the Bishop. Another precious historical relic is the baptismal font sculpted in sandstone dating from 1522. Above the entrance to the cupola - capped chapel there is a Maltese cross. The chapel's altar has a wooden crucifix from the middle of the 17th century particularly venerated by the congregation. In the crypt beneath the chapel lie buried, among others, its founder and the last Poznań Commander, Andrzej Miaskowski.
Restoring diplomatic ties between Poland and the Order of Maltese Knights made it possible for the Johannites to resume their activities. Today next to the church there is an oncology clinic run by the John of Jerusalem Foundation from Malta.