Pius V instituted "Our Lady of Victory" as an annual feast to commemorate the victory at Lepanto, which he attributed to the Blessed Virgin Mary.

Dedications to Our Lady of Victory had preceded this papal declaration.
In particular, Simon de Montfort, 5th Earl of Leicester built the first shrine dedicated to Our Lady of Victory in thanks for the Catholic victory over the Albigensians at the Battle of Muret on September 12, 1213.
In thanksgiving for victory at the Battle of Bouvines in July 1214, Philip Augustus of France founded the Abbey of Notre Dame de la Victoire, between Senlis and Mont l'Evêque.

In 1573, Pope Gregory XIII changed the title of the "Feast of Our Lady of Victory" to "Feast of the Holy Rosary", to be celebrated on the first Sunday of October.
Dominican friar Juan Lopez in his 1584 book on the rosary states that the feast of the rosary was offered "in memory and in perpetual gratitude of the miraculous victory that the Lord gave to his Christian people that day against the Turkish armada".

In 1671 the observance of this festival was extended by Clement X to the whole of Spain, and somewhat later Clement XI, after the  victory over the Turks gained by Prince Eugene in the  Battle of Petrovaradin on 5 August 1716 (the feast of Our Lady of the Snows), commanded the feast of the Rosary to be celebrated by the universal Church.

Leo XIII raised the feast to the rank of a double of the second class and  added to the Litany of Loreto the invocation "Queen of the Most Holy Rosary".
On this feast, in every church in which the Rosary confraternity has been duly erected, a plenary indulgence toties quoties is granted upon certain conditions to all who visit therein the Rosary chapel or statue of Our Lady.
This has been called the "Portiuncula" of the Rosary.

Pius X in 1913 changed the date to 7 October, as part of his effort to restore celebration of the liturgy of the Sundays.
In 1960 under Pope John XXIII it is listed under the title "Feast of the Blessed Virgin Mary of the Rosary"; and under the 1969 liturgical reforms of Pope Paul VI "Our Lady of the Rosary" is mentioned as a mandatory memorial.
Pius V instituted "Our Lady of Victory" as an annual feast to commemorate the victory at Lepanto, which he attributed to the Blessed Virgin Mary.
Dedications to Our Lady of Victory had preceded this papal declaration. In particular, Simon de Montfort, 5th Earl of Leicester built the first shrine dedicated to Our Lady of Victory in thanks for the Catholic victory over the Albigensians at the Battle of Muret on September 12, 1213. In thanksgiving for victory at the Battle of Bouvines in July 1214, Philip Augustus of France founded the Abbey of Notre Dame de la Victoire, between Senlis and Mont l'Evêque.
In 1573, Pope Gregory XIII changed the title of the "Feast of Our Lady of Victory" to "Feast of the Holy Rosary", to be celebrated on the first Sunday of October. Dominican friar Juan Lopez in his 1584 book on the rosary states that the feast of the rosary was offered "in memory and in perpetual gratitude of the miraculous victory that the Lord gave to his Christian people that day against the Turkish armada".
In 1671 the observance of this festival was extended by Clement X to the whole of Spain, and somewhat later Clement XI, after the  victory over the Turks gained by Prince Eugene in the  Battle of Petrovaradin on 5 August 1716 (the feast of Our Lady of the Snows), commanded the feast of the Rosary to be celebrated by the universal Church.
Leo XIII raised the feast to the rank of a double of the second class and  added to the Litany of Loreto the invocation "Queen of the Most Holy Rosary". On this feast, in every church in which the Rosary confraternity has been duly erected, a plenary indulgence toties quoties is granted upon certain conditions to all who visit therein the Rosary chapel or statue of Our Lady. This has been called the "Portiuncula" of the Rosary.
Pius X in 1913 changed the date to 7 October, as part of his effort to restore celebration of the liturgy of the Sundays. In 1960 under Pope John XXIII it is listed under the title "Feast of the Blessed Virgin Mary of the Rosary"; and under the 1969 liturgical reforms of Pope Paul VI "Our Lady of the Rosary" is mentioned as a mandatory memorial.
Our Lady of the Rosary