 Although some masters at the University of Paris spent decades teaching there, it was the custom of the Dominican order (as with the Franciscans) to rotate scholars through these positions. Accordingly, in 1259 Aquinas was sent back to Italy, where he spent most of the following decade in several Dominican houses of study, first in Orvieto (in Umbria) and then in Rome. During these years, while he continued to preach, lecture on the Bible, and conduct academic disputations, he found the time to develop his two most important works, the Summa contra gentiles and the Summa theologiae.