St. Dominic de Guzman
Died: August 6, 1221
Feast Day: August 8
Patron Saint of: astronomers
Saint Dominic was born into nobility in Calarvega, Spain. During his lifetime, he was a champion for the Church against the Albigensians - a fight which was aided by the Blessed Mother. The Albigensian Heresy taught that there are two Gods, marriage is a sin, and denied the Trinity, incarnation and redemption.
At the age of 26, Dominic became a cathedral canon to a bishop whose mission was to convert Albigensians back to the orthodox teachings of the Church. At that time, most heresies and other false teachings were handled with by force by the likes of Simon de Montfort, whose armies leveled entire cities and slaughtered many of the cities' inhabitants in the south of France. Dominic, however, believed that the most effective way to counteract these errors was by reason.
Saint Dominic founded the Order of Preachers, which is known today as the Dominicans.