The construction of the church and monastery began around 1275 on the initiative of prince Bolesław the Pious and his wife Jolenta. Shortly thereafter, duke Przemysł II began building the Poor Clares monastery, where the duchess Jolenta had to find shelter. The one-nave church of the Poor Clares was probably ready in 1283. Only later further work was begun in the Franciscan church. Its construction was probably completed around 1295. Churches and monastery buildings were burnt down in 1613. After reconstruction, and especially after a thorough reconstruction in the second half In the 18th century, they lost many of their original style features. In 1836, the Prussian authorities closed the Franciscan monastery, a year later the same fate affected the Poor Clares. The Franciscan monastery was occupied by the army, and the Poor Clares house was demolished at the turn of the sixties and seventies of the 19th century. The Franciscans returned to their former seat in 1928. In the years 1930-32 they carried out the restoration of the temple, restoring it in part to gothic forms.
Early gothic church of the Assumption of the Virgin Mary and Saint Antoni is a one-nave building with an extended chancel. Its present northern nave is the former oratory of the Poor Clares. From the west there is a four-storey, four-sided tower, covered with a pyramid roof, erected in the 15th century. The church outside is clasped with buttresses. Above the nave and chancel there is a common gable roof, and the oratory is covered with a mono-pitched roof. The presbytery is covered with an early gothic rib vault. The pseudo-gothic vault of the nave was founded in 1930-32. From the medieval monastery buildings only the foundations remained on which in the eighteenth century a new monastery was erected.
Webpage regionwielkopolska.pl, Kościół klasztorny franciszkanów pw. Wniebowzięcia NMP i św. Antoniego w Gnieźnie.