Large-scale consumer borrowing is a relatively recent phenomenon. Since antiquity, however, individuals have contracted debts for a variety of reasons. The criticism of interest-bearing loans is similarly old, and has been denounced as usury. In his Commentaries on the Laws of England, published between 1765 and 1769, William Blackstone commented that "When money is lent on a contract to receive not only the principal sum again, but also an increase by way of compensation for the use, the increase is called interest by those who think it lawful, and usury by those who do not."
In 1311, Pope Clement V established an absolute ban on usury throughout Christian Europe. By the last quarter of the fourteenth century, however, English law recognized penal bonds that enforced a penalty twice the rate of the loan in case of even partial late repayment of the debt. Regardless of any prohibitions, interest-bearing loans existed, but were relatively uncommon through the nineteenth century and were limited mainly to mortgages. In the beginning of the twentieth century, and the emergence of more expensive household appliances and automobiles, consumer credit expanded rapidly. The late twentieth century saw massive expansion of consumer credit and household debt that only began to decline in the early twenty-first century as a result of the financial crisis of 2008.