The word rosary comes from a Medieval custom: to put a crown of roses on the statues of the Virgin, these roses were symbol of the beautiful and fragrant prayers addressed to Mary. Thus was born the idea of using a string of beads (the crown) to guide the meditation. In the thirteenth century, Cistercian monks worked out, from this series a new prayer, which they called rosary, as compared to the mystic offers of a wreath of roses to the Virgin. This devotion was popularized by St. Dominic, who, according to tradition, received in 1214 the first rosary from the Virgin Mary, the first of a series of appearances as a means to convert non-believers and sinners.

Rosary - Wikipedia