Tonguez
A suffusion of yellow
Khorod said:AFAIK, letters of marque were given to 'pirate hunters' because the nation didn't have the naval forces or training to take care of the matter themselves. On land, the army, guard, etc, would have been able to take care of such matters.
No Letters of Marque were used by the British Government (at least) to licence private mecenary ships to attack Spanish and/or Dutch shipping. For instance Sir Francis Drake was a Privateer operating under such a letter of Marque.The Privateer was licenced to raid foriegn shipping and take cargoes returning a portion of it to the Crown as payment.
Sometimes if the Privateer was getting desperate they would turn to piracy themselves. One of the reasons Bucanners thrived in the Caribbean for so long was because the British colonies supported their attacks on Spanish settlements and ships.
Generally too Medieval armies were not contiguous units but were instead distinct bands of Knights, men-at-arms and foot soldiers lead by their particular Lord. Each Lord was technically independent however as most were close relatives of the King and held position by his favour they were generally loyal.
The point though is that each Lord was free to break away and return to the north if they so chose.
Mecenaries in such a setting are those not attached to a Lord but instead able to be hired by anyone willing to pay.
Of course, if most of the army is on the southern border fighting a war their might easily be room for expanding into mercenary security for those not conscripted into the army. Or maybe the last generation was wasted, along with the national resources. Its all the nation can do to maintain the integrity of the borders and prevent civil unrest, so selling letters of marque in an effort to get semi-official security wouldn't be a bad idea.