Siege coins from Leiden, 1574. When towns were besieged for long periods money would often become scarce. In order to pay the soldiers who defended the town, for example, special coins were minted. When there was no more gold or silver, copper and tin were used. Coins were even made of pieces of layered paper. One of these paper coins from Leiden bears the motto: Haec Libertatis Ergo, 'this (is endured) for freedom'.