St. Dominic de Guzman
St. Dominic de Guzman was a priest, and preacher against many heresies of his day. Dominic helped to reform monastic orders, such as the Cistercians, and later founded an order that was devoted to the conversion of the Albigensian heretics. It was in 1215 that Dominic founded and gained approval for an order of preachers that came to be known as the Dominicans. Dominic spent the last year of his life, organizing the order and recruiting members. St. Dominic is the patron of Astronomers. His feast day is celebrated on August 8th.