As a young priest Dominic served as a canon at the cathedral of Osma, Spain. In 1206 his bishop, Diego de Acebo, became the unofficial leader of a papal mission to Languedoc, in southern France. There the Albigensian heresy, which maintained that all material creation was evil, had made alarming inroads among the population. The bishop chose Dominic as his companion, and they went about the region preaching, living simply, and setting an example of poverty, humility, and virtue. To avenge the Albigenses’ murder of the papal legate, Pope Innocent III ordered a military campaign against them. During the five years of civil war that ensued, from 1207 to 1212, Dominic and his followers continued in their mission of converting the Albigenses by example and persuasion rather than force, concentrating on the cities of Beziers, Carcassonne, and Toulouse, the main areas of heresy.
Because of his conduct and character, Dominic was successful in preaching and converting the heretics when other clergy were not, for he demonstrated that an authentic preacher of the Gospel was one who lived according to its teachings. In 1215 Dominic was able to establish his headquarters in Toulouse. About this time he envisioned the idea of an order of preachers–a body of highly trained preachers living certain elements of the monastic tradition, bound by vows with emphasis on obedience, but devoted to the active work of preaching and teaching anywhere and everywhere.
The above excerpt is from Reflections of Dominican Spirituality: The Windows of St. Dominic Church, Washington, D.C. by Dr. Mary Moran.