St. Dominic who Gave Us the Rosary! Founder of the Dominican Order - Patron Saint of Astronomers - Saint of August 8

 Saint Dominic Order Preachers (in Spanish: Santo Domingo; 8 August 1170 – 6 August 1221), also known as Dominic de Guzmán, was a Castilian Catholic priest founder of the Dominican Order and patron saint of astronomers. He is also known as Dominic of Osma, Dominic of Caleruega, and Domingo Félix de Guzmán. 

Legend says that his mother, who was unable to conceive, made a pilgrimage to the Abbey at Silos, and dreamt that a dog leapt from her womb carrying a flaming torch in its mouth, and seemed to set the earth on fire. This story possibly occurred when his order became known, after his name, as the Dominican order, Dominicanus in Latin and a play on words interpreted as Domini canis: "Dog of the Lord."
The Order of Preachers, is commonly known as the Dominican Order. Dominic was born at Calaroga, in Old Castile, c. 1170; and died on the 6th of August, 1221. His parents, Felix Guzman and Joanna of Aza, undoubtedly belonged to the nobility of Spain, though probably neither was connected with the reigning house of Castile, as some of the saint's biographers assert. Of Felix Guzman, personally, little is known, except that he was in every sense the worthy head of a family of saints.

To nobility of blood Joanna of Aza added a nobility of soul which so enshrined her in the popular veneration that in 1828 she was solemnly beatified by Leo XII. The example of such parents was not without its effect upon their children.
In 1191, during a famine in Spain, young Dominic gave away his money and sold his clothes, furniture, and even precious manuscripts to feed the hungry.
In 1215, Dominic established himself, with six followers, in a house given by Peter Seila, a rich resident of Toulouse. Dominic saw the need for a new type of organization to address the spiritual needs of the growing cities of the era, one that would combine dedication and systematic education, with more organizational flexibility than either monastic orders or the secular clergy. He subjected himself and his companions to the monastic rules of prayer and penance; Bishop Foulques gave them written authority to preach throughout the territory of Toulouse. Also in 1215, the year of the Fourth Lateran Council, Dominic and Foulques went to Rome to secure the approval of the Pope, Innocent III. Dominic returned to Rome a year later, and was finally granted written authority in December 1216 and January 1217 by the new pope, Honorius III, for him to form the Ordo Praedicatorum ("Order of Preachers").

Not only Saint Dominic but also his brothers, Antonio and Manes, were distinguished for their extraordinary sanctity. Antonio, the eldest, became a secular priest and, having distributed his patrimony to the poor, entered a hospital where he spent his life ministering to the sick. Manes, following in the footsteps of Dominic, became a Friar Preacher, and was beatified by Gregory XVI.
According to a Dominican tradition, in 1208 the rosary was given to St. Dominic in an apparition by the Blessed Virgin Mary in the church of Prouille. This Marian apparition received the title of Our Lady of the Rosary.
Sources: The CATHOLIC ENCYCLOPEDIA and Wikipedia