While some communities already existed, some eremites began to band together into communities. St. Pachomius is considered the father of cenobitic monasticism, allegedly at the prompting of an angel. Or he could have received the insight to use the same billeting as the Roman army, in which he had served at one time.
This was a couple of centuries before St. Benedict.
Then times changed (where have we heard that before?), and with homeless masses gathering in the cities, this gave rise to the mendicant orders. The most famous are the Franciscans and Dominicans: