Speyer Cathedral, officially the Imperial Cathedral Basilica of the Assumption and St Stephen, in Latin: Domus sanctae Mariae Spirae (German: Dom zu Unserer lieben Frau in Speyer) in Speyer, Germany, is the seat of the Roman Catholic Bishop of Speyer and is suffragan to the Roman Catholic Archdiocese of Bamberg. The cathedral, which is dedicated to St. Mary, patron saint of Speyer ("Patrona Spirensis") and St. Stephen is generally known as the Kaiserdom zu Speyer (Imperial Cathedral of Speyer). Pope Pius XI raised Speyer Cathedral to the rank of a minor basilica of the Roman Catholic Church in 1925. Begun in 1030 under Konrad II, with the east end and high vault of 1090–1103, the imposing triple-aisled vaulted basilica of red sandstone is the "culmination of a design which was extremely influential in the subsequent development of Romanesque architecture during the 11th and 12th centuries". As the burial site for Salian, Staufer and Habsburg emperors and kings the cathedral is regarded as a symbol of imperial power. With the Abbey of Cluny in ruins, it remains the largest Romanesque church. It is considered to be "a turning point in European architecture", one of the most important architectural monuments of its time and one of the finest Romanesque monuments. In 1981, the cathedral was added to the UNESCO World Heritage List of culturally important sites as "a major monument of Romanesque art in the German Empire". History and architecture Middle ages In 1025, Conrad II ordered the construction of the Christian Western world's largest church in Speyer which was also supposed to be his last resting place. Construction began 1030 on the site of a former basilica which stood on an elevated plateau right by the Rhine but safe from high water. Along with Santiago de Compostela (begun 1075), Cluny Abbey (Cluny III, begun 1085), and Durham Cathedral (begun 1093), it was the most ambitious project of the time. The red sandstone for the building came from the mountains of the Palatine Forest and is thought to have been shipped down the channelled Speyerbach, a stream running from the mountains into the Rhine at Speyer. Neither Conrad II, nor his son Henry III, were to see the cathedral completed. Conrad II died in 1039 and was buried in the cathedral while it was still under construction; Henry III was laid next to him in 1056. The graves were placed in the