power behind the throne, the

The person or group who has true control or a great influence on one in control, but is not officially or publicly in charge. The president's charisma and likability got him elected, but his team of advisors is the real power behind the throne.

Fig. the person who actually controls the person who is apparently in charge. Mr. Smith appears to run the shop, but his brother is the power behind the throne. They say that the vice president is the power behind the throne.

A person with great influence who stays behind the scenes and has no apparent authority. For example, Harry may be the CEO, but it's obvious that his wife is the power behind the throne. [Mid-1800s]

If you describe someone as the power behind the throne, you mean that they are really the person that has power although another person is officially in charge. She was the real power behind the throne, a strong and determined woman controlling a weaker husband for her own aims.

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.