St. Dominic de Guzman was born in Old Castile in 1170. Born into Spanish nobility, he was the son of Blessed Joan of Aza. While pregnant with her son, Blessed Joan of Aza had a vision that her child would be a dog who caught the world on fire with the torch he carried in his mouth. A dog with the torch later became the symbol for the Dominicans, the order St. Dominic founded in 1215. St. Dominic worked for clerical reform, fought heresies and spread the devotion to the rosary. He died in August 1221. When St. Dominic was baptized, his mother saw a star on his chest and that is the reason he is patron saint of astronomy.