This church is one of the oldest stone-built religious buildings in all of Poland, with some of the eldest relics dating back to the 10th century. In fact, it has been around for so long that its floor is actually situated roughly two meters under the current level of the square, which was covered with different layers of pavement throughout the centuries. The church underwent several renovations according to the style that was fashionable from one era to the next, but it has remained relatively untouched since it was revamped in Baroque style in the 1610s. In opposition to the grand and voluminous St. Mary’s Basilica on the other end of the square, St. Adalbert Church is actually quite small and confined.
According to the legend, the church was erected on the site where St. Adalbert preached a famous sermon before he left on a mission to bring Christianity to Prussia that would lead him to his untimely and martyr death – it was later on proven by records that this was not the case and that St. Adalbert was alive and well as the official priest of the church for the better part of his life.