This memorial (originally Our Lady of Victories) commemorates the battle of Lepanto (7 Oct 1571), when a Christian fleet defeated the Turks. The victory was attributed by Pius V to the recitation of the Holy Rosary. This great Marian prayer is sometimes traced back to St Dominic and his confreres, preaching against the Albigensian heresy in the thirteenth century, although it seems more likely to have taken its familiar form in the fifteenth century. Since then it has spread all over the world and has produced marvellous fruits, bringing countless Christians “to Jesus through Mary.” – CTS New Daily Roman Missal 2012, p 3047