Pope St Pius V

Pope St Pius V (1566-1572)

Born Antony Ghislieri on January 17, 1504, he was raised by poor parents and entered the Dominican Order with whom he was ordained in 1528 and taught philosophy and theology in Dominican colleges . He quickly became bishop and Cardinal and followed his predecessor, the easy-going Pope Pius IV in 1566. He started his Papacy by implementing the reform of the Council of Trent. He cleaned up the curia, excommunicated heretical bishops, cleaned up the immorality in the church and swept the church clean – paving the way for the great surge in the church we call the Counter Reformation. He also excommunicated the tyrant Elizabeth I of England and formed the Holy League – a confederation of Catholic armies which eventually defeated the Ottoman Empire at the Battle of Lepanto. Pius V also instituted the Feast of Our Lady of Victories.
Pope Pius V also published the catechism of Trent and improved the breviary and the Roman Missal, which was still being used until 1962. He tried to clean Rome from any immorality, forbidding bull fights and even tried to stop bull fighting from Spain, one of the few things he was unsuccessful in. He died on May 1, 1572 and was canonized by Pope Clement XI in 1712. 

Pope Francis visits the tomb of Pope St Pius V

Since he was a Dominican, he frequently kept using the white cassock or habit that Dominicans used, and the custom remained that successive Popes kept using  white, possibly to beat the summer Roman heat. And that is why the Popes still uses white as the color of his cassock. And the first thing Pope Francis did when he was elected Pope was the visit Santa Maria Maggiore and pay tribute to the tomb of Pope St Pius V.