Joseph's family was wealthy
Once he was finished with school, however, his father had plans for him, intending that Joseph carry on the family line.
Then Joseph got sick - and nearly died. After he recovered, he knew he had to follow his own way. He became a priest.
He proved to be an excellent priest, working in a parish and in various positions in the Diocese: reviving zeal among laity and clergy alike. After several years, he realized that he had to go further. He gave away his fortune and went to Rome where he ministered to the noblest and to the lowest members of society.
When he tried to enroll poor outcast children in school, he was met with stiff resistance from many quarters. So, he started his own school and his own order to teach the poor children.
His work continued to meet with external resistance. Some were afraid that educating the poor would cause unrest. Some religious orders were jealous. Joseph's friendship with a controversial scientist was also troubling to some Church leaders.
Later, when Joseph was a very old man, members of the order he himself had founded turned against him. He would be vindicated, but the dissension took its toll. The order was dissolved two years before Joseph died, at very ripe age of 91 on this very day in 1648.
The next year, Joseph's order, the Piarists, was resurrected and continues even now. St. Joseph Calasanz was canonized in the following century.
(from an earlier post)