Since the earliest days of the Church, people have used prayer beads or cords with knots in them to help them keep track of their prayers. (This practice is not limited to Catholicism, by the way; prayer beads are also found in religions such as Hinduism and Orthodox Christianity.) Christian monks used to pray the 150 psalms, and since lay people were not able to memorize 150 separate psalms, many began praying 150 Our Fathers. In the Middle Ages, a time when the “Hail Mary” prayer became widely known, it became common for people to pray 150 Hail Marys instead. This developed into the rosary as it is prayed now. There is an old tradition in the Church that Mary herself appeared to St. Dominic (1170-1221) and gave him the rosary to help him as he preached against the Albigensian heresy, a heresy which denied the Incarnation of Christ.
When praying each decade of the rosary, Catholics meditate on key moments in the life of Christ, called “mysteries.” By the late fifteenth century, the mysteries of the rosary looked almost exactly like the Joyful, Sorrowful, and Glorious mysteries that we pray today. In 2002, the rosary was enriched by the addition of five new mysteries suggested by Pope John Paul II. These are called the Luminous mysteries and are a testament to the fact that the rosary continues to inspire prayer and new ways to engage with Christ.