From the early Church Fathers to now.
Hail Mary, full of grace, the Lord is with thee; blessed art thou amongst women, and blessed is the fruit of thy womb, Jesus. Holy Mary, Mother of God, pray for us sinners, now and at the hour of our death. Amen.
The Rosary joins vocal prayer to meditation: the Apostles' Creed, the Our Father, ten Hail Marys and the Glory Be, told on beads across the mysteries of Christ's life — the Joyful, the Sorrowful and the Glorious (with the Luminous added in 2002).
The early monks repeat short prayers by the hundred, counting them on pebbles laid aside or on knotted cords — the ancestor of the prayer-rope and, later, the rosary bead.
In medieval monasticism the hundred and fifty Psalms come to be paralleled by a hundred and fifty Angelic Salutations (Hail Marys) — "Our Lady's Psalter," the seed of the Rosary's form.
By pious tradition Our Lady appeared to St. Dominic during the Albigensian crisis and gave him the Rosary to preach against heresy. The devotion in fact developed gradually, and this tradition is itself first attested only in the fifteenth century.
The Dominican Alanus de Rupe (Alan de la Roche) founds the first Rosary confraternities and spreads the fifteen-decade devotion across northern Europe — the beginning of the Rosary as a mass practice.
By the bull Consueverunt Romani, Pope St. Pius V — himself a Dominican — establishes the received form: fifteen decades of Hail Marys with the Our Father, meditating the mysteries of the life, death and glory of Christ.
The Christian fleet's victory over the Ottoman navy at Lepanto, on the first Sunday of October, is ascribed to the Rosary confraternities praying at Rome; Pius V orders a yearly commemoration.
Pope Gregory XIII establishes the feast of the Holy Rosary on the first Sunday of October, in thanksgiving for Lepanto — later fixed by Clement XI (1716) to the whole Church.
“It has always been the habit of Catholics in danger and in troublous times to fly for refuge to Mary, and to seek for peace in her maternal goodness; showing that the Catholic Church has always, and with justice, put all her hope and trust in the Mother of God.”
“…all the clues converged upon one point, the preaching of the Dominican Alan de Rupe about the years 1470-75. He it undoubtedly was who first suggested the idea that the devotion of "Our Lady's Psalter" (a hundred and fifty Hail Marys) was instituted or revived by St. Dominic.”
In the apparitions at Fatima the daily praying of the Rosary is asked for the peace of the world — binding the devotion, in the modern mind, to prayer for peace.
In the apostolic letter Rosarium Virginis Mariae, Pope St. John Paul II proposes five new "Mysteries of Light" — the first change to the Rosary's structure in four centuries. (The letter's text is under copyright.)
The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.