The Observant Franciscans (wearing brown habits), who in Poland were commonly called Bernardines, after St Bernard, arrived in Poznań in 1455. Initially they erected a wooden chapel outside the city walls, in Piaski, and by 1473 the chapel made way for a brick church. This Gothic structure was destroyed in 1655 by the Swedes stationed in Poznań. They feared that the church complex outside the city walls might be used for cover by the attacking Polish army. A new Baroque church was built in the years 1661-68 under the supervision of first Krzysztof Bonadura senior and then Jerzy Catenazzi. In 1725 gale winds tore down the roof of the church. During the reconstruction carried out between 1730-38, the facade was modified and open - work domes designed by Jan Stier of Leszno were added on top of the spires. The statues of saints in the niches of the elevation were made by Franciszek Domusberg of Wschowa. Around 1740 the nave was extended by the Chapel of Our Lady of Loretta. After the closure of the monastery in 1835, the Prussian authorities handed over the church to a local grammar school, which used it as lodgings for its male pupils. In 1945 the building suffered serious damages: the roof of the chancel and the domes of the spires came down and the interior was gutted by fire. The monastery was also devastated. After the war the Franciscans returned to their former seat and began renovation work that was to last many years. Reconstruction of the domes was completed in 1982 and the north wing was restored as late as in 1988.
The highlight of the structure is its Baroque facade flanked by two spires measuring 29 metres each and capped with domes. The single nave interior and the slightly lower, extended chancel were restored to their mid-17th century Baroque form. The interior was restored according to old exemplars. The only original item is the 18th century relief with a passion scene placed over the rood - screen arch. The statues of the twelve apostles on the pillars come from the first half of the 18th century, but they were only restored after WWII. The floor of the church is raised a few metres above the level of Bernardyński Square, which has in the past prevented the church from flooding. In 1980 a cracked bell was placed in front of the church. It bears the names of Francis of Assisi and Jan Kapistran and was cast in Poznań in 1730.