The appearance of the mendicant Orders was the most significant event of the Church’s interior life during the thirteenth century. Not from the seclusion of their cloister, nor even through the lecture-room, would this new class of monks influence the mass of Christians. Their approach was more direct; their method a form of preaching better suited to the aspirations of mankind at large.
The extraordinary success of the mendicants goes to prove that they satisfied an urgent need. The stream of vocations soon became a torrent: in the second half of the thirteenth century, for example, the Franciscans had 25,000 religious and 1,100 houses; by 1316 there were 30,000 friars in 1,400 convents. The growth of the Dominican Order was not quite so rapid. Its emphasis upon intellectual attainments and its relative indifference to popular forms of devotion tended to limit the number of vocations. Nevertheless, it counted 7,000 members in 1256, 10,000 friars with 600 priories in 1303, and 12,000 in 1337.
Henri Daniel-Rops, Cathedral and Crusade: Studies of the Medieval Church (1050-1350)