By the 13th century, people wanted to observe traditional prayer times with private devotions. Because people could not read, they could not pray the psalms. Eventually they substituted 150 Our Fathers for the 150 Psalms Later the Our Fathers were replaced with more simple Hail Mary’s, spaced with meditation on the lives of Jesus and Mary. St. Dominic spread the popularity of devotion of the rosary through his preaching.
There are twenty mysteries reflected upon in the Rosary, and these are divided into the five Joyful Mysteries (said on Monday and Saturday), the five Luminous Mysteries (said on Thursday), the five Sorrowful Mysteries (said on Tuesday and Friday), and the five Glorious Mysteries (said on Wednesday and Sunday). As an exception, the Joyful Mysteries may be said on Sundays during Advent and Christmas, while the Sorrowful Mysteries may be said on the Sundays of Lent.