For centuries before Christ, people prayed repetitively and used rocks, pebbles, stones, prayer ropes, knots, wood pieces, and eventually beads to keep count. In third-century Egypt, Christian hermits and monks known as the Desert Fathers used stones and later prayer ropes while praying the 150 Psalms. Pope Gregory the Great, from 590-604, popularized an early form of the Hail Mary by asking that it be prayed on the fourth Sunday of Advent, and many people then began repeating the prayer with beads. By the beginning of the ninth century, monks recited all 150 Psalms daily, sometimes adding Gabriel's words from Luke 1:28 after each Psalm, and counted their prayers by moving pebbles from one place to another. As people near the monasteries sought to imitate this devotion, monks taught those who could not read or write to pray Our Fathers or Hail Marys in place of the Psalms, in counts of 50 or 150 each day or at least weekly, a practice known as the poor man's breviary. In 1365, Henry of Kalkar divided the 150 prayers into 15 groups of 10 Hail Marys, with an Our Father between each group. In the early fifteenth century, monastic prayer further developed as monks contemplated Christ's life while praying, and between 1410 and 1439 Dominic, a Prussian monk, introduced the mysteries of the rosary as phrases forming a brief story of the life of Christ and his mother. In 1480, a Dominican priest simplified the devotion by reducing the meditation points to 15 episodes, later known as the Mysteries, so people could meditate more deeply during each decade. In 1569, Saint Pope Pius V officially approved the rosary in the form of 15 decades of Hail Marys introduced by the Our Father and concluded with the Glory Be, establishing the devotion in the Catholic Church. The rosary gained great popularity in the 1500s during the threat posed by Muslim Turks in Eastern Europe and the Mediterranean, and in 1571 Pius V organized a fleet under Don Juan of Austria and asked the faithful to pray the rosary under the title Our Lady of Victory; after the Muslim defeat at the Battle of Lepanto on October 7, 1571, he established the Feast of the Holy Rosary on October 7, 1572. By the end of the fifteenth century, the rosary's basic structure was in place as Our Fathers dividing decades of Hail Marys with meditations on the lives of Christ and Mary, and in the sixteenth century the Joyful, Sorrowful, and Glorious Mysteries began to emerge, the Glory Be was added to each decade, and the second half of the Hail Mary was formalized. After the full development of the Hail Mary prayer, the term rosary was given in 1597, and both the Hail Mary and the rosary remained unchanged in form until 1917. On May 13, 1917, Mary appeared to three shepherd children in Fatima, Portugal, told them to return on the 13th day for the next six months, and asked them to pray the rosary every day for world peace; on July 13, 1917, she asked that a short prayer now called the Fatima Prayer be added to the end of each decade. On October 16, 2002, Saint Pope John Paul II proposed the Luminous Mysteries. Today, Roman Catholics use a rosary of 59 beads, with 6 large beads for the Our Father and 53 smaller beads for the Hail Mary, along with prayers including the Sign of the Cross, Apostles' Creed, Glory Be, Fatima Prayer, Hail, Holy Queen, and the Rosary Prayer.