Monastic Life and Rule
David established an exceptionally austere monastic community. By his Rule the monks pulled the plough themselves without draught animals, ate only bread with salt and herbs, and drank only water, from which they took the name 'watermen.' They kept a vegetarian discipline, consuming no meat or beer.
The brethren held no personal possessions; the tradition records that even to say 'my book' was reckoned an offence. The evenings were given to prayer, reading, and writing. David founded monastic settlements and churches in Wales, in Dumnonia (Cornwall), and in Brittany.