foundation · 323 · Egypt
Pachomius, an ex-soldier converted by the charity of Christians to prisoners, founded at Tabennisi (c. 323) the first koinonia — monks living a common life under a written rule. The leap from hermit to community is his: Basil took it to Cappadocia, Benedict to Italy, and monasticism became an institution.
The cenobitic rule: monks in community under obedience — the form Basil, Benedict and the whole monastic world would build on.