Joseph Calasanz (; ), (September 11, 1557 – August 25, 1648), also known as Joseph Calasanctius and Iosephus a Mater Dei, was a Spanish Catholic priest, educator and the founder of the Pious Schools, providing free education to the sons of the poor, and the religious order that ran them, commonly known as the Piarists. He was a close friend of the renowned astronomer Galileo Galilei. He is honored as a saint by the Catholic Church. Early life Calasanz was born at the Castle of Calasanz near Peralta De La Sal in the Kingdom of Aragon, on September 11, 1556, the youngest of the eight children, and second son, of Pedro de Calasanz y de Mur, an infanzón (minor nobleman) and town mayor, and María Gastón y de Sala. He had two sisters, Marta and Cristina. His parents gave him a good education at home and then at the elementary school of Peralta. In 1569, he was sent for classical studies to a college in Estadilla run by the friars of the Trinitarian Order. While there, at the age of 14, he determined that he wanted to become a priest. This calling, however, met with no support from his parents. For his higher studies, Calasanz took up philosophy and law at the University of Lleida, where he earned the degree of Doctor of Laws cum laude. After those studies, he began a theological course at the University of Valencia and at Complutense University, then still at its original site in Alcalá de Henares. Joseph's mother and brother having died, his father wanted him to marry and carry on the family. But a sickness in 1582 soon brought Joseph to the brink of the grave, which caused his father to relent. On his recovery, he was ordained a priest on December 17, 1583, by Hugo Ambrosio de Moncada, Bishop of Urgel. During his ecclesiastical career in Spain, Calasanz held various offices in his native region. He began his ministry in the Diocese of Albarracín, where Bishop de la Figuera appointed him his theologian, confessor, synodal examiner, and procurator. When the bishop was transferred to Lleida, Calasanz followed him to the new diocese. During that period, he spent several years in La Seu d'Urgell. As secretary of the cathedral chapter, Calasanz had broad administrative responsibilities. In Claverol, he established a foundation that distributed food to the poor. In October 1585, de la