He's the company president, but his assistant is 'the (real) power behind the throne'.
In Shakespeare's play, Macbeth kills the king and 'ascends to the throne'.
He 'ascended the throne' [=became king] after the death of his father.
(..) If war comes to Westeros, will the Knights of the Vale fight for their king? Young Lor Robin hees my avice. An I have always counsele loyalty to the throne. Goo. If there's nothing else. There is another matter, Your Grace. Something so urgent I couln't (..)2015 TvShow: Game of Thrones Title: Unbowed, Unbent, Unbroken Season: 5 Episode 6
(..) your reams come true. You comman her army, sail to Westeros, efeat all your enemies an watch her climb those steps an sit on the Iron Throne. Hurrah. Long live the queen. Then what? Then she rules. So a woman who has not spent a single ay of her ault life (..)2015 TvShow: Game of Thrones Title: Unbowed, Unbent, Unbroken Season: 5 Episode 6