Soldiers of Fortune, or Mercenaries, have been used in war since the advent of war itself. The Persians, the Romans, the Greeks all used mercenaries in their armies. The trend continued into the middle ages when German Landsknechts and Swiss Pikemen were in high demand. Other famous mercenary groups include Cossacks, Ronin, and Pirates.
Now, the standard definition of Mercenaries is given to us by Article 47 of Protocol I of the 1949 Geneva Convention, which states that mercenaries are neither combatants nor prisoners of war. Currently, the most popular form of mercenary is the PMC (Private Military Contractor), which supplies soldiers to governments to help them guard high profile targets, defend installations, train local police, and so on.
Bounty Hunters are also still used by bail bondsmen to ensure that their clients go to court when they are supposed to.
Soldier of Fortune Magazine is designed to be read by the mercenary.For more information, read:
Military History Magazine (June 2003): Cossack Pirates in the Black Sea
CNN Special on MercenariesMilitary History Podcast is sponsored by Armchair General Magazine