St. Dominic de Guzman was from a wealthy Spanish family, as well as the son of Bl. Joan of Aza. While she was pregnant with Dominic, she had a vision of a black and white dog with a torch in his mouth, setting the world on fire. The dog was Dominic, and the dog with a torch in his mouth later became the symbol for the order which Dominic founded.
During the time of Dominic's ministry of preaching to the heretics, he received a vision of Our Lady in which she showed him the rosary and told him to say it daily and to teach it to all who would listen to him, saying that eventually the true faith would win out. While Dominic is sometime credited with inventing the rosary, it in truth pre-dates him. He is, however, correctly credited for being the one who popularized it.
An interesting fact about St. Dominic and his order, is that the Pope had a dream of Dominic supporting the crumbling church with his shoulder. The same Pope had a very similar dream of St. Francis a few years earlier. It is said that the two saints met during visits to Rome, at which St. Dominic exclaimed "You are my companion and must walk with me. If we hold together, no earthly power can withstand us."
St. Dominic is the patron astronomers, astronomy, scientists, the falsely accused, as well as my family. He is represented as holding a rosary and a tall cross, a lily, or with a dog and a globe, fire, a rosary or a star shining above his head.
A man who governs his passions is master of his world. We must either command them or be enslaved by them. It is better to be a hammer than an anvil. - Saint Dominic
St. Dominic de Guzman. . . . Pray for Us!