From 1797 until 1821, the monetary pressures of fighting a
lengthy, expensive war against France led Britain to suspend
convertibility – the exchange of paper credit for gold. The
ensuing expansion of credit helped Britain’s banking system meet
the demands placed on it by both a wartime government and a
rapidly industrializing society. However, it was not without its
problems: new £1 and £2 banknotes were hastily introduced, and
were immediately the subject of enormous forgery . In 1801,
8,000 forged notes were detected . Improved note design reduced
the rate of detected forgeries to about 3,000 per year. An 1812
Act of Parliament stipulated that only the Bank of England could
use notes with white letters on a black background, and the
country banks were given time to redesign and print their own
notes. The plethora of transitory designs that emerged during
this period provided excellent opportunities for forgery: over
the period 1811–20, detected £1 note forgeries rose again, by
more than 500 . Counterfeitin