The Patriarchal Cathedral Basilica of Saint Mark (officially known in Italian as the Basilica Cattedrale Patriarcale di San Marco and commonly known as Saint Mark's Basilica) is thecathedral church of the Roman Catholic Archdiocese of Venice, northern Italy. It is the most famous of the city's churches and one of the best known examples of Italo-Byzantine architecture. It lies at the eastern end of the Piazza San Marco, adjacent and connected to theDoge's Palace. Originally it was the chapel of the Doge, and has only been the city's cathedral since 1807, when it became the seat of the Patriarch of Venice,^[1] archbishop of the Roman Catholic Archdiocese of Venice, formerly at San Pietro di Castello..