The prince, king, or emperor stamped his own device or portrait upon the coin; hence the term seigniorage from _seignior_ (meaning lord or ruler).

Seigniorage meant primarily the right the ruler, or the estate, has to charge for coinage, and hence it has come to mean also the charge made for coinage, and often, in a still broader sense, the profit made by the government in issuing any kind of money with a value higher than that of the materials (whether metal or paper) composing it.

Coinage is rarely without charge, and often has been a source of revenue to the ruler.

In antiquity and in the Middle Ages this right was frequently exercised by princes for their selfish advantage to the injury and unsettling of trade.

This introduced a very great problem of value into the use of money.
The coinage is said to be _gratuitous_ when no charge is made for coinage.