The Catholic Piarist schools were established in 1600 and by 1632 were being opened at a rate of one every seven months. They had been founded by a Spaniard as a way to educate impoverished children. In 1646 they were closed down by the pope.
The reason for the closure and the scandal that was hidden in the archives of the Vatican for centuries, is the subject of Karen Liebreich's very readable and detail-rich book Fallen Order: Intrigue, Heresy, and Scandal in the Rome of Galileo and Caravaggio.
Liebreich (a wonderful German pun in the name) was a scholar at the prestigious European University Institute who was given access to the Vatican archives as part of the research she was doing. What she discovered was a scandal reminiscent of recent events in the United States where the Catholic hierarchy covered up child abuse by priests. The "initial cover-up was ordered by no less a man than the patron saint of all Christian schools."
Liebreich's research took her into "dusty cupboards" and the archives of the Inquisition.