Pope Pius IV (; 31 March 1499 – 9 December 1565), born Giovanni Angelo Medici, was head of the Catholic Church and ruler of the Papal States from 25 December 1559 to his death in December 1565. Born in Milan, his family considered itself a branch of the House of Medici and used the same coat of arms. Although modern historians have found no proof of this connection, the Medici of Florence recognized the claims of the Medici of Milan in the early 16th century. Pope Paul III appointed Medici Archbishop of Ragusa, and sent him on diplomatic missions to Germany and Hungary. He presided over the final session of the Council of Trent. His nephew, Cardinal Charles Borromeo, was a close adviser. As pope, Pius IV initiated a number of building projects in Rome, including one to improve the water supply. Life Early life Giovanni Angelo Medici was born in Milan on 31 March 1499 as the second of eleven children to Bernardino Medici and Clelia Serbelloni. Giovanni Medici was the younger brother of condottiero Gian Giacomo Medici, and the maternal uncle of Charles Borromeo. Medici studied philosophy and medicine in Pavia. After studying at University of Bologna and acquiring a reputation as a jurist he obtained his doctorate in both canon and civil law on 11 May 1525. Medici went in 1527 to Rome, and as a favourite of Pope Paul III was rapidly promoted to the governorship of several towns, the archbishopric of Ragusa (1545–1553), and the vice-legateship of Bologna. Cardinalate On 8 April 1549, Pope Paul III made Medici a cardinal, receiving his red hat and titular church title on the following 10 May. Under Papal authority, he was sent on diplomatic missions to Germany and also to Hungary. Pontificate Election On the death of Pope Paul IV, he was elected pope on 25 December 1559, taking the name Pius IV, and installed on 6 January 1560. His first public acts of importance were to grant a general pardon to the participants in the riot after the death of his predecessor, and to bring to trial the nephews of his predecessor. One, Cardinal Carlo Carafa, was strangled, and Duke Giovanni Carafa of Paliano, with his nearest associates, was beheaded. Council of Trent On 18 January 1562 the Council of Trent, which had been suspended by Pope Julius III, was convened by Pius IV for the third