For hundreds of years the Piarist Order of priests has been known for its history of important contributions to education, science, and culture. Throughout Italy, Spain, and central Europe, the order's schools evolved from shelters created to educate poor children into exclusive private academies. Thousands of children were educated at Piarist schools, including Mozart, Goya, Schubert, Victor Hugo, Johann Mendel, and a host of astronomers, kings, emperors, presidents, even a pope. Yet in 1646, the Piarist Order was abruptly abolished by Pope Innocent X, an unprecedented step not seen since...