Marshalsea

The Marshalsea (1373–1842) was a notorious prison in Southwark, Surrey (now London), just south of the River Thames. It housed a variety of prisoners over the centuries, including men accused of crimes at sea and political figures charged with sedition, but it became known, in particular, for its incarceration of the poorest of London's debtors. Over half the population of England's prisons in the 18th century were in jail because of debt.