After the establishment of the first archbishopric in 968 on Ostrów Tumski, Mieszko I built the first three-aisled basilica. A rotunda dating from 965 had previously stood on this site. The church was destroyed in 1038-1039 and later rebuilt in the Romanesque style. In the 13th century, a new Gothic presbytery was built and in the 14th century a Gothic nave was added. In the following centuries, the church was further expanded with new chapels and other additions. In the 17th century, it was rebuilt in the Baroque style. The church suffered damage from fires and wars but was repeatedly restored. It was heavily damaged in 1945 during the Battle of Poznań. Reconstruction was carried out between 1948 and 1956, mainly restoring its Gothic appearance. The entrance to the cathedral leads through Gothic portals and bronze doors from the late 20th century. Above them there is a large Gothic window. The cathedral has a basilica layout with an ambulatory, two side aisles and numerous chapels. Inside, there are various types of vaulting. In the presbytery there is a Gothic altarpiece from 1512, as well as other valuable works such as old choir stalls, sculptures, and a baptismal font. There is also a modern altar from 1971. A stone plaque in the floor commemorates the first bishop, Jordan, and the early rulers of Poland. The cathedral also contains old tombs and epitaphs of important figures. In the side aisles and chapels there are numerous works of art, mainly tombs and paintings from different periods. Particularly important are two chapels: the Golden Chapel, which contains the sarcophagi of the first rulers of Poland, and the Royal Chapel with a monument to Przemysł II. Beneath the church are remains of very old structures as well as the burial sites of former rulers and archbishops.