Saint Dominic de Guzman was born in 1170 at Calaruega, Castile, the son of Felix Guzman and Blessed Joan of Aza, who named him after Saint Domingo de Silos. When pregnant with Dominic, his mother had a vision that her unborn child was a dog who would set the world on fire with a torch it carried in its mouth; a dog bearing a torch in its mouth became a symbol for the Dominicans.
He studied at the University of Palencia, was probably ordained there while pursuing his studies and was appointed canon at Osma in 1199. There he became prior superior of the chapter, which was noted for its strict adherence to the rule of St. Benedict. In 1203 he accompanied Bishop Diego de Avezedo of Osma to Languedoc where Dominic preached against the Albigensian heresy and helped reform the Cistercians. Dominic founded an institute for women at Prouille in Albigensian territory in 1206 and attached several preaching friars to it.
When papal legate Peter of Castelnan was murdered by the Albigensians in 1208, Pope Innocent III launched a crusade against them headed by Count Simon IV of Montfort which was to continue for the next seven years. Dominic followed the army and preached to the Albigensians, but with no great success.
In 1214 Simon gave him a castle at Casseneuil and Dominic, with six followers, founded an order devoted to the conversion of the Albigensians; the order was canonically approved by the bishop of Toulouse the following year. He failed to gain approval for his order of preachers at the fourth General Council of the Lateran in 1215; however, he received Pope Honorius III's approval the following year, and the Order of Preachers (Fratri Predicatori) was founded.
Dominic spent the last years of his life organizing the order, travelling all over Italy, Spain and France preaching and establishing new houses. He convoked the first general council of the order at Bologna in 1220 and died there the following year on August 6, 1221, having returned from a preaching tour in Hungary. He was canonised in 1234.