These statistical indications of declining productivity of the soil are supported by the overwhelming evidence of the poverty of the fourteenth century peasantry--poverty which can be explained only by the barrenness of their land. Many of the features of the agrarian changes of this period are familiar--the substitution of money payments for villain services, the frequency of desertion, the amalgamation and leasing of bond-holdings, the subdividing and leasing of the demesne. A point which has not been dwelt upon is the favorable pecuniary terms upon which the villains commuted their services. Where customary relations were replaced by a new bargain, the bargain was always in favor of the tenant. What was the source of this strategic advantage of the villain? The great number of holdings made vacant by the Black Death and the scarcity of eligible holders placed the landowner at a disadvantage, but this situation was temporary. How can the difficulty of filling vacant tenements before the Black Death be accounted for, and why were villains still able to secure reductions in their rents a generation after its effects had ceased to be felt? Even before the Black Death, it was frequently the case that villain holdings could be filled only by compulsion. The difficulty in finding tenants did not originate in the decrease in the population caused by the pestilence. There is little evidence that there was a lack of men qualified to hold land even after the Black Death, but it is certain that they sought in every way possible to avoid land-holding. The villains who were eligible in many cases fled, so that it became exceedingly difficult to fill a tenement when once it became vacant. Land whose holders died of the pestilence was still without tenants twenty-five and thirty years later, although persistent attempts had been made to force men to take it up. When compulsion succeeded only in driving men away from the manor, numerous concessions were made in the attempt to make land-holding more attractive. It is important to notice that these concessions were economic, not social. The force which was driving men away was not the desire to escape the incidents of serfdom, but the impossibility of making a living from holdings burdened with heavy rents. These burdens were eased, grudgingly, little by little, by landlords who had exhausted other methods of keeping their land from being deserted. It was necessary to reduce the rent in some way in order to permit the villains to live. The produce of a customary holding was no longer sufficient to maintain life and to allow the holder to render the services and pay the rent which had been fixed in an earlier century when the soil was more fertile. Notices of vacated holdings date from before 1220 on the estates of the Berkeleys. Thomas the First was lord of Berkeley between 1220 and 1243, and