Thomas Aquinas was born at the end of 1224 or the beginning of 1225 in Roccasecca, not far from Naples. He was the scion of a prominent noble family, the counts of Aquino. Aquinas received his earliest education at the Benedictine Abbey of Monte Cassino. In 1239 he went to the University of Naples to study the liberal arts.

In Naples Aquinas became acquainted with the relatively new Order of Friar Preachers, better known as the Dominicans. Like the Franciscans, whose order was founded during the same period, the Dominicans were mendicants, radicalizing the evangelical ideal of poverty. Unlike the Benedictines, the Dominicans did not tie themselves to one specific cloister. Their life was therefore marked by a high degree of mobility. The Dominicans were the first religious order to make devotion to study one of its main objectives; in keeping with this aim they established study houses in university cities throughout Europe. In 1244 Aquinas decided to join the new order, much against the will of his family, who apparently had other plans for him. He was detained for a year in the family castle of Roccasecca, but his family finally accepted Aquinas’s decision.