By means of the papal bull of 1570, "Regnans in Excelsis", Pius V excommunicated Elizabeth I of England for heresy and persecution of English Catholics during her reign. He also arranged the formation of the Holy League, an alliance of Catholic states to combat the advancement of the Ottoman Empire in Eastern Europe. Although outnumbered, the Holy League famously defeated the Ottomans at the Battle of Lepanto in 1571. Pius V attributed the victory to the intercession of the Blessed Virgin Mary and instituted the feast of Our Lady of Victory. Biographers report that as the Battle of Lepanto ended, Pius rose and went over to a window, where he stood gazing toward the East. "...ooking 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'."