Built in 1269 by the Knights Hospitallers of Saint John of Jerusalem, the chapel was enlarged in 1351. Around 1500 a side chapel was added, while 20 years later, (unfinished) mural paintings of great stylistic quality, depicting the life of St. John the Baptist and the Passion of Christ, were executed. With the Reformation, the Knights of St. John left the city and in 1798 their possessions were finally seized and sold. The chapel then became a brewery and then a blacksmith’s workshop, before being listed as a historical monument in 1893.