A first cathedral was erected in the mid-10th century, but it was lost during the Great Slav Rising. The present building was started in 1165, built from bricks and designed in a late-Romanesque to early-Gothic style. It is considered the "cradle" of Brandenburg and "mother" of all churches in the state. The cathedral is situated on an island (Dominsel) in the River Havel which also contains the cathedral's enclosure, the former knight academy, curiae, cathedral canon's houses and the Gothic St Peter's Chapel.