Born in the Burgos town of Caleruega in 1170 into a family related to the kings of Castile, Leon, Aragon, Navarra and Portugal, at the early age of six he already expressed his clear religious vocation and his desires. to accumulate knowledge.

He trained in Humanities, Philosophy and Theology, becoming Canon Regular of the Osma Cathedral and royal ambassador among other positions of responsibility. But it was his entrepreneurial character and tireless preacher that laid the foundations for his most important legacy. Convinced of his missionary vocation and that he had to contribute to stopping the discontent that arose in the south of France against the rules dictated from Rome by the then called "Cathar heretics", he began his private crusade to convince them of their error, creating a movement of preachers that would later give rise to the Dominican Order.