St. Dominic founded the Order of Preachers in response to the Albigensian heresy.
What could be so troubling about the Albigensians? They sound like they would be friendly neighbors. But they called themselves “Cathars”. Ooooh. That sounds nefarious. It get’s worse.
They believed there to be two gods, a bad one who made all material things and a good one who made all spiritual things. Since they regarded everything physical as wicked, they discouraged sex, food and just about everything else. Suicide was recommended and the end of the human race was one of their goals. Read more in The Catholic Encyclopedia.
These Cathars proved unimpressed and unconverted despite the tepid efforts of ignorant and decadent clergy.
In come the Dominicans.
St. Dominic was canonized in 1234,
just thirteen years after his death.