The feast of the Holy Rosary was instituted by Pope Pius V to celebrate the anniversary of the defeat of the Turkish fleet at the battle of Lepanto on the first Sunday in October 1571, which ended the threat of Muslim domination of the Mediterranean and was ascribed in part to the prayers and processions of the Rosary confraternity in Rome. Later the feast was moved to the fixed date of 7 October.
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Collect
Pour forth, we beseech you, O Lord,
your grace into our hearts,
that we, to whom the Incarnation of Christ your Son
was made known by the message of an Angel,
may, through the intercession of the Blessed Virgin Mary,
by his Passion and Cross
be brought to the glory of his Resurrection.
Who lives and reigns with you in the unity of the Holy Spirit,
God, for ever and ever.
Amen.