A mora was an ancient Spartan military unit of about a tenth of the Spartan army, at approx. 600 men by modern estimates, although Xenophon places it at 6,000. This can be reconciled by the nature of the Spartan army with an organisation based on year classes, with only the younger troops being mobilised for all but the gravest emergencies. Either way, it was the largest tactical unit in Sparta, if not all Greece, and was often the only force sent out on campaign.