History of the Rosary
To learn about the history of the Rosary, we look to Church tradition. According to Church tradition, the rosary was given to St. Dominic in an apparition by the Blessed Virgin Mary in the year 1214 in the church of Prouille. This Marian apparition received the title of Our Lady of the Rosary. In the 15th centruy it was promoted by Blessed Alanus de Rupe (aka Alain de la Roche or Saint Alan of the Rock), a learned Domionican priest and theologian, and established the "15 rosary promises" and established many rosary confraternities. However, most scholarly research suggests a more gradual and organic development of the rosary.
The practice of meditation during the praying of the Hail Marys is attributed to Dominic of Prussia (1382-1460), a Carthusian monk, who called it "Life of Jesus Rosary". The German monk added a sentence to each of the 50 Hail Marys already popular at his time, using quotes from scripture. In 1569, the Dominican Pope Pius V officially established the devotion to the rosary in the Catholic Church.
The history of the Rosary continues from the 16th to the early 20th century, the structure of the rosary remained essentially unchanged. There were 15 mysteries, one for each of the 15 decades. In the 20th century, the addition of the Fatima Prayer to the end of each decade became popular. There were no other changes until 2002 when Pope John Paul II instituted 5 new Luminous Mysteries.