The Rosary is another ancient devotion in the Church. The practice of praying the Rosary dates back to the High Middle Ages as a substitute to reciting the Divine Office for individuals who could not read. So instead of reading the 150 psalms, people would say 150 Our Fathers which they counted off on a ring of beads.
During the 12th century, Marian devotions became popular and the use of the Hail Mary was infused into the reciting of the Our Father in the Rosary. As time went on the Rosary evolved into what we have today which reflects the history of salvation.
The Rosary is divided into mysteries. Each mystery is a reflection of the life a Jesus and Mary:
      The Joyful Mystery
             The Annunciation
             Mary Visits Her Cousin Elizabeth
             The Birth of Jesus
             The Presentation of Jesus in the Temple
             The Finding of Jesus in the Temple 

       The Sorrowful Mystery
             The Agony in the Garden of Gethsemane
             The Scourging at the Pillar
             The Crowning With Thorns
             Jesus Carries His Cross to Calvary
             Jesus Dies on the Cross 

        The Glorious Mystery
            The Resurrection of Jesus
            The Ascension Into Heaven
            The Descent of the Holy Spirit

            The Assumption of Mary Into Heaven
            The Coronation of Mary as Queen of Heaven

        The Luminous Mysteries of Light (Created by Pope John Paul II on October 16, 2002)
            Jesus’ Baptism in the Jordan
Jesus’ Self-Manifestation at the Wedding Feast in Cana
His Proclamation of the Kingdom of God, with His Calls to Conversion
Jesus’ Transfiguration
His Institution of the Eucharist, the Sacramental Reenactment of the Paschal Mystery