The Diocese of Orlando marked the feast day of St. Dominic on Monday.

“St. Dominic, patron saint of astronomers, the Dominican Republic, and founder of the Dominicans, pray for us!” the diocese posted online.

St. Dominic was born in Spain in the 12th century. His parents were members of the nobility. He joined a religious community when he was in his 20s, Britannica says. While he was traveling abroad with the Bishop of Osmo, Dominic saw that Albigensian heretics were a threat to the Church in France. Those heretics were teaching that anything concerning the body - including eating, drinking and procreating - was evil. Dominic and the bishop set their minds to converting the heretics. To succeed in their effort, they needed to practice austerity, which included living in poverty and traveling barefoot.

That effort marked the beginning of Dominic's "evangelical preaching." Britannica says Dominic successfully converted about 16 heretics, who in return followed him. The group worked to establish a religious order devoted to preaching, and in 2016 Pope Honorius III officially recognized the Dominican Order.

St. Dominic's feast day is celebrated every Aug. 8, Franciscan Media says.

Today, the Dominican Order's website says the order is comprised of many friars, nuns, sisters, and lay people who adhere to St. Dominic's mission of teaching, preaching, studying, and praying. Dominican friars can be found to be engaged in campus ministry efforts at universities. They also lead retreats, missions and workshops, serve as chaplains in hospitals and convents, and serve as missionaries.