These were specially selected Diplomats (by a King or Queen), who had full “discretionary” power overseas – when they represented their Ruler. In Most cases, Trade issues (even Alliances requiring force of arms), required the single (and only approval) of a Ruler. Plenipotentiary Diplomats could make instant decisions on behalf of their Monarch. They were normally extremely well educated and respected men (who answered to only their Monarch). The Title is seen as early as the 9th Century.