St Petronius himself founded this church in 433 and called it Monte Oliveto. Originally it was round, and as full of Holy Land symbolism as his Santo Stefano. One of Bologna's most prestigious, it changed its dedication to St John the Evangelist and then in the 11th century became the church of the Augustinian Canons Regular of the Lateran, who built rebuilt it in a more traditional Latin cross and later added a beautiful lobed Renaissance façade, reminiscent of the marble-faced churches of Venice, only here done in rose-tinted brick. It boasts one of the tallest bell towers in Bologna.
The church was full of art that was stripped away by Napoleon but eventually returned, although some of the best bits were relocated in museums, including the famous Ecstasy of St Cecilia by Raphael and Perugino's Madonna and Saints, now both in the Pinacoteca. In the early 19th century the floor began to collapse, so all the old tombs were moved; during the Second World War the church was gravely damaged in an aerial bombardment, and was restored by 1950.
Image by Mike Peel (www.mikepeel.net); Creative Commons