Usury is the lending of money at high interest rates something that was damned as sinful in medieval England. There many religions condemning the practice with similar statements such as ‘Those who charge usury are in the same position as controlled by the Devil’s influence. Those who persist in usury, they incur Hell’.
However, Jews carried out the practise in England by disguising interest payments. Noblemen and barons would lend money to Jewish communities to lend out to other citizens. The interest rates were around 30 to 40% and this made repayment of loans difficult for peasants who would often took out loans. If the noblemen recalled the money lent to the Jews and they were unable to pay they would have them murdered. In order to make the business profitable and spread the risk the Jews would lend across society.
Edward I borrowed money to fund various campaigns at home and in France until he had borrowed all the money the Jews had and then had them expelled from England. As it was only Jews who had circumvented the law Edward then turned to Italian financial lenders who by the 13th century had realised the profits in the lending markets and was becoming a growing industry.