Church of San Giovanni degli Eremiti (St. John of the Hermits) in Palermo; Sicily (2018)The church's origins date to the 6th century. Later; after the Islamic conquest of Sicily; it was converted into a mosque. After the establishment of the Norman domination of southern Italy; it was returned to the Christians by Roger II of Sicily who; around 1136; entrusted it to the Benedictine monks of Saint William of Vercelli.