Today is the memorial of Our Lady of the Rosary.
The Battle of Lepanto took place on 7 October 1571 when a galley fleet of the Holy League, a coalition of the Republic of Venice, the Papacy (under Pope Pius V), Spain (including Naples, Sicily and Sardinia), the Republic of Genoa, the Duchy of Savoy, the Knights Hospitaller and others, decisively defeated the main fleet of Ottoman war galleys.
Victory gave the Holy League temporary control over the Mediterranean, protected Rome from invasion, and prevented the Ottomans from advancing into Europe (Wikipedia).
The victory is attributed to Rosary processions made at Rome on that same day and thereby to the intercession of Our Lady. Pope Pius V established the feast of Our Lady of Victory for the anniversary of that battle. Gregory XIII in 1573 expanded the celebration of the feast and changed the name to Feast of the Holy Rosary. Through subsequent centuries Clement X and Clement XI extended the celebration further. Leo XIII added to the Litany of Loreto the invocation “Queen of the Most Holy Rosary”. (See Catholic Encyclopedia)
In 1969, Pope Paul VI changed the name of the feast to “Our Lady of the Rosary.”
Pope John Paul II issued his apostolic letter Mane Nobiscum Domine on October 7, 2004, for the year of the Eucharist, encouraging a contemplation of the face of Christ with Mary.