A Letter of Marque was used to grant authority to arm a private ship. Since in earlier times kingdoms and governments did not have navy's, they would instead license private ships (privateers) to capture their enemies' shipping and goods. These licenses were called Letters of Marque, and have been issued since the thirteenth century. The privateers sailed under the protection of Letters of Marque as they captured ships, with the booty and plunder being divided between the issuing government & the vessel.