On October 7, Catholics remember Our Lady of the Rosary.
The feast was actually instituted under another name: In 1571 Pope Pius V instituted “Our Lady of Victory” as an annual feast in thanksgiving for Mary’s patronage in the victory of the Holy League over the Muslim Turks in the Battle of Lepanto. Two years later, in 1573, Pope Gregory XIII changed the title of this feastday to “Feast of the Holy Rosary.” And in 1716, Pope Clement XI extended the feast to the whole of the Latin Rite, inserting it into the Roman Catholic calendar of saints, and assigning it to the first Sunday in October. In 1913, Pope Pius X changed the date to October 7, as part of his effort to restore celebration of the liturgy of the Sundays.
The Battle of Lepanto
On October 7, 1571, a patchwork fleet of Catholic ships primarily from Spain, Venice and Genoa, under the command of Don Juan of Austria, was at a distinct disadvantage. The much larger fleet of the Ottoman Empire—a force with 12,000 to 15,000 Christian slaves as rowers—was extending toward Europe.
However, St. Pope Pius V, realizing that the Muslim Turks had a decided material advantage, called upon all of Europe to pray the Rosary for victory. Christians gathered in villages and towns to pray as the sea battle raged; and at the hour of victory the pope—who was hundreds of miles away at the Vatican—is said to have gotten up from a meeting, walked over to an open window exclaiming “The Christian fleet is victorious!” and shed tears of joy and thanksgiving to God.
The epic victory has been commemorated in literature: Miguel de Cervantes, a Spanish soldier wounded in the battle, recovered to become a novelist, poet and playwright; and he was so inspired by this battle that he incorporated elements of it in his own acclaimed novel, Don Quixote. And philosopher/writer and Christian apologist G.K. Chesterton retold the story in his 1915 ballad, Lepanto.