Coup d'état

According to John Brent, a coup d'etat (also known as coup) was what occurred when the army took control over its own nation. (PROSE: Time and Relative)

Bernice Summerfield described it as "when one government replaces another in a hostile, aggressive and very non-democratic manner". (AUDIO: Professor Bernice Summerfield and the Bone of Contention)

On Gallifrey
President Flavia was overthrown in a coup. (AUDIO: Lies)

Coordinator Romana and Lady Livia led an attempted coup against President Eternal Rassilon. However, they were unsuccessful. (AUDIO: Assassins)

The Twelfth Doctor led a coup against Rassilon which resulted in his exile from Gallifrey. (TV: Hell Bent)