It took a generation for the council to materialise, partly due to papal fears over potentially renewing a schism over conciliarism; partly because Lutherans demanded the exclusion of the papacy from the Council; partly because of ongoing political rivalries between France and the Holy Roman Empire; and partly due to the Turkish dangers in the Mediterranean. Under Pope Clement VII (1523–34), troops of the Catholic Holy Roman Emperor Charles V sacked Papal Rome in 1527, "raping, killing, burning, stealing, the like had not been seen since the Vandals". Saint Peter's Basilica and the Sistine Chapel were used for horses. Pope Clement, fearful of the potential for more violence, delayed calling the Council.