From the Catholic Encyclopedia:
He worked incessantly to unite the Christian princes against the hereditary enemy, the Turks. In the first year of his pontificate he had ordered a solemn jubilee, exhorting the faithful to penance and almsgiving to obtain the victory from God. He supported the Knights of Malta, sent money for the fortification of the free towns of Italy, furnished monthly contributions to the Christians of Hungary, and endeavoured especially to bring Maximilian, Philip II , and Charles I together for the defence of Christendom. In 1567 for the same purpose he collected from all convents one-tenth of their revenues. In 1570 when Solyman II attacked Cyprus, threatening all Christianity in the West, he never rested till he united the forces of Venice, Spain, and the Holy See. He sent his blessing to Don John of Austria, the commander-in-chief of the expedition, recommending him to leave behind all soldiers of evil life, and promising him the victory if he did so. He ordered public prayers, and increased his own supplications to heaven. On the day of the Battle of Lepanto, 7 Oct., 1571, he was working with the cardinals, when, suddenly, interrupting his work opening the window and looking at the sky, he cried out, "A truce to business; our great task at present is to thank God for the victory which He has just given the Christian army". He burst into tears when he heard of the victory, which dealt the Turkish power a blow from which it never recovered. In memory of this triumph he instituted for the first Sunday of October the feast of the Rosary, and added to the Litany of Loreto the supplication "Help of Christians ". He was hoping to put an end to the power of Islam by forming a general alliance of the Italian cities Poland, France, and all Christian Europe, and had begun negotiations for this purpose when he died of gravel, repeating "O Lord, increase my sufferings and my patience!" He left the memory of a rare virtue and an unfailing and inflexible integrity. He was beatified by Clement X in 1672, and canonized by Clement XI in 1712.
The tomb of Pope St. Pius V, in the Church of Santa Maria Maggiore, Rome