If angels were to govern men, neither external nor internal controls on government would be necessary.@ - Federalist #51. The doctrine of sovereign immunity is an ancient legal principle, dating back to feudal Europe, when power flowed from the King down through the nobility and very little trickled down to the peasantry. It is rooted in the premise that to submit to the jurisdiction of a court implies that one is subservient or inferior to the power of that court.