A study of the Hundred Years War reveals a well-organised trading market in English and French soldiers.
One soldier claimed to have been taken prisoner 17 times, says historian Dr Remy Ambuhl.
The protected and financially valuable status of soldiers saw the first use of the phrase “prisoner of war”.
Historian Dr Ambuhl says that ransoming prisoners captured in medieval battles was much more common across all ranks of soldiers than had previously been understood.
His study of documents from the Hundred Years War, between 1337 and 1453, reveals an unexpected level of contractual and financial arrangements surrounding the swapping of all kinds of prisoners, not just knights and nobles.