Finally the situation became so bad, according to the chroniclers, that anyone going to market with a whole pound of pennies could find scarcely twelves acceptable to the merchants. News of this reached Henry in Normandy. It troubled him, for bad coins meant a loss of revenue. He had all the moneyers gathered at Winchester, where each had his right hand amputated in addition to other serious mutilation. Thus Henry upheld the important principle of a sound treasury.
(from A History of England and the British Empire)