They did this, first of all, by setting the rate of multure - that part of the gram that was taken as payment for the milling service - very high.
Lords were, in fact, on the horns of a dilemma when they tried over-zealously to impose suit of mill or to raise multure rates, since such attempts also tended to discourage outside customers.
This was most strikingly evident at Wirksworth, Derbyshire, where a thirteenth-century attempt to raise the multure rate from one-twentieth to one-fourteenth seems to have been a direct copy of practice further north.(88) More generally, it showed itself in a sort of middle ground of medium-sized mill values in the north-west midlands in particular (that is, Cheshire, Staffordshire and Derbyshire), where quite high-valued mills occurred fairly frequently.