An individual with so much influence on a king, president, or other nominal leader that he or she is the de facto leader. The idea, although certainly much older, was first expressed in this way by William Pitt in a 1770 speech: “There is something behind the throne greater than the King himself.” Among the numerous historical examples are the Russian monk Rasputin, who had enormous sway over his country’s last czar, and First Lady Nancy Reagan, who was believed to have similar influence on President Ronald Reagan. See also gray eminence.