Joseph Calasanz was born in 1557 in the region of Aragon, Spain. After his studies he was ordained a priest, served in several Spanish dioceses, and then went to Rome.

In Rome he saw poor children growing up on the streets without schooling, and he opened a school that charged them nothing. For this work he founded the Piarist order. In his last years conflicts inside and outside the order led to its being severely reduced, a trial he bore with obedience and patience. He died in 1648, past the age of ninety, and the order was later restored. He was canonized in 1767.