It is hard to pinpoint the origin of the Rosary. “Prayer beads” or use of beads to keep track of the number of repeated prayers as an aid to meditation come from some of the earliest days of the Church, tracing itself to the desert monasteries in the first few centuries. By the time the Middle-ages arrived, a string of beads had been developed called “Paternosters” (Latin for Our Father) that kept track of Our Fathers and Hail Marys. It wasn’t until the 1500’s that the Rosary took it’s final form. It is believed that the rosary began as a substitute for the Divine Office, the normal prayer of the monks, when the laity became unable to pray the office in Latin due to a combination of time, illiteracy, and the movement of the European languages away from Latin. The 150 Hail Marys replaced the 150 psalms, offered by the laity in communion with the monastic orders in remembering Jesus throughout the day. In the 14th century a Carthusian monk divided the Rosary into decades, by which one could intersperse 15 Our Fathers. Over time the mysteries were added to the Rosary by a Dominican, which allowed the illiterate a way to reflect upon the various events in the lives of Jesus and Mary.
It is said that St. Dominic received the Rosary from the Blessed Virgin and used it in his preaching against the heresy of Albigensianism, a cousin of Gnosticism. This claim however, is unfounded, since this story did not become known until 200 years after Dominic’s death, the Dominican constitutions of that time don’t link him with it, and the contemporary hagiography does not ascribe it to him. There may be a grain in truth in it, that Dominic did preach it, perhaps even under the mandate of Our Lady, but it was already in existence by his time.
The Rosary finally secured itself in popular Catholic devotion during the 1500’s, when Muslim Turks were invading Eastern Europe. Control of the Mediterranean soon became at stake so in 1571, Pope St. Pius V organized a fleet under the command of Don Juan of Austria. While preparations were underway, the Holy Father asked all of the faithful to say the rosary and implore our Blessed Mother’s prayers, under the title Our Lady of Victory, that our Lord would grant victory to the Christians. Although the Muslim fleet outnumbered that of the Christians in both vessels and sailors, the forces were ready to meet in battle. The Christian flagship flew a blue banner depicting Christ crucified and another banner with the image of Our Lady of Guadalupe a recent apparition from Mexico that had just been approved. On October 7, 1571, the Muslims were defeated at Lepanto. The following year, Pope St. Pius V established the Feast of the Holy Rosary on October 7, encouraging the faithful to not only remember this victory, but also give thanks to the Lord for all of His benefits and remember the powerful intercession of our Blessed Mother. This feast day, as a testament to the power of the Rosary, is still celebrated every year on October 7th.
During the apparition of Fatima in 1917, Our Lady asked that the prayer “O My Jesus” be added after each decade. On October 16, 2002, Pope St. John Paul II declared that the following year would be a year of the Rosary. During that year, in his encyclical Rosarium Virginis Mariae, St. John Paul added 5 new mysteries to the Rosary which he called the “Luminous Mysteries” or mysteries of light.