Noun
power behind the throne (plural powers behind the throne or powers behind thrones)
(idiomatic) Someone who appears to be without special status, but who has great covert influence on a person in authority.
Burghley: William Cecil at the Court of Elizabeth I (Yale University Press, 2008); sees him as power behind the throne * Beckingsale, B. W. Burghley: Tudor statesman (1967) * Collinson, Patrick. Source: Internet
And this is where Muhammad bin Salman (pictured), the 30-year-old deputy crown prince who is the power behind the throne of his elderly father, King Salman, receives foreign guests in a walled complex. Source: Internet
Valentinian II was a very young man, little more than a figurehead, with Arbogast as the true power behind the throne. Source: Internet
Although he was also offered the opportunity to be tlatoani, Tlacaelel preferred to operate as the power behind the throne. Source: Internet
They held the title of Augusta as well, indicating that they may have been the power behind the throne. Source: Internet
“By 1924, Kent Parrot had become the power behind the throne in Los Angeles municipal politics. Source: Internet