The Durham rolls range from 1296 to 1384; those of Halesowen from 1272 to 1307. Neither series is unbroken, and the gaps are sometimes serious. But the Durham rolls are almost continuous from 1366 to 1384 inclusive; and this gives us fairly safe ground for statistical argument over that period; and, even in the most broken years, certain things come out very clearly.

There is no question, for instance, as to the enforcement of some of the heaviest burdens. Of these the worst, in the immediate and pecuniary sense, was undoubtedly the heriot with its companion the mortuary. When a serf died, the lord of the manor could claim his best beast, while the rector took his second best. For this there were definite historical reasons. The heriot (hergeat, or war-apparatus) had formerly been due at every tenant's death. The overlord to whom he owed military service had supplied him with the necessary weapons, which at death reverted to their original owner; the heriot was thus the resumption of a horse and armour which in legal theory had only been lent. Long before the time with which we are dealing, however, freemen had practically shaken themselves free, or rather, the system had died at the root; no horse and armour had been lent, and there was nothing to resume. But from the servile household the lord still took the best beast or, failing that, his best chattel—melius averium or melius catallum.