Historian Peter Earle has described the two sides of the Christian-Muslim Mediterranean conflict as "mirror image of maritime predation, two businesslike fleets of plunderers set against each other". This conflict of faith in the form of privateering, piracy and slave raiding generated a complex system that was upheld/financed/operated on the trade in plunder and slaves that was generated from a low-intensive conflict, as well as the need for protection from violence. The system has been described as a "massive, multinational protection racket", the Christian side of which was not ended until 1798 in the Napoleonic Wars. The Barbary corsairs were finally quelled as late as the 1830s, effectively ending the last vestiges of counter-crusading jihad.