Dominic was born in Caleruega, Castile, Spain, after 1170. First educated by an uncle who was a priest, he was later sent to Palencia to study arts and theology. There, Dominic sold his books to provide for the needs of the victims of a local famine. He then joined the chapter of the regular canons of Osma, under the priorship of Diego de Acebes. Engaged in a demanding form of life, he left the cloister in 1203 or 1204 to accompany Diego, already bishop, to Northern Europe on a diplomatic mission. Crossing the region of Toulouse, he discovered the Albigensian heresy, which then ravaged the South of France. A missionary desire grew in Dominic and he wanted to make Christ known to the pagans.

In 1215, the group moved to Toulouse to a house provided by Pierre Seilhan. Upon Dominic’s return from visiting the Lateran council, the small group of preachers adopted the rule of Saint Augustine and the customs of the Premonstratensians. On December 22, 1216, the Pope confirmed the community of Toulouse and, on January 21, 1217, he used the name « preachers » to designate the vocation of the brothers. Dominic’s missionary call was universal. In 1217, he dispersed the small group of his brothers. Some left for Spain, others for Paris, others still supported the nuns of Prouilhe. Dominic himself went to Italy to report to the Pope on his action. He sent brothers to Bologna. Like Paris, this city was an important university centre. Vocations flowed in; the Order adopted laws and organized itself into provinces during the first General Chapters celebrated in 1220 and 1221. Dominic, exhausted, died in Bologna on August 6, 1221, on his return from a preaching mission in Lombardy. Pope Gregory IX canonized him in 1234.