Canon 18 Clergy displaced by invasion must return to their churches

Clerics who, by reason of a barbarian incursion, or otherwise in some way through circumstance, have migrated elsewhere, we command, whenever the occasion has ceased for them, or the incursions of the barbarians on account of which they made their withdrawal, to return again to their own churches, and not to leave them for long without excuse. And if anyone does not conduct himself according to the present canon, let him be excommunicated until he runs back to his own church. And let this same thing be done also in the case of the bishop who detains him.