Countess (Players)
The Countess was the name assumed by a Player whilst on Earth. She was a high ranking member of the Players, tasked with causing chaos in human history under the guise of giving her people amusement.
She tried helping Napoleon Bonaparte to win the Napoleonic Wars, but have his Empire collapse and cause more internecine conflicts, thus creating the potential for more games. Also, she and the Count attempted to kidnap Winston Churchill and deliver him to Germany. Both plans were stopped by the Second Doctor when their activities caught the attention of the Time Lords. (PROSE: World Game)
The Count and Countess sent an assassin to kill Churchill during the Boer Wars, but were stopped by the Sixth Doctor. In a later struggle, the Countess accidentally shot and killed the Count. She was not mad at the Doctor, but invited him to join the Players' Game, since he manipulated history like them. The Doctor denied what he did was the same thing, so the Countess left with the Count's body. (PROSE: Players)
Deciding that the time had come for an Endgame so that they could move on to other worlds, the Players attempted to start World War III in 1951. In Russia, the Countess seduced Josef Stalin, and whispered into his ear whilst he slept that China and America were aiming nuclear missiles at his cities. The Eighth Doctor convinced her to abort her game. She saw more potential to destroy the Earth in its future, so the Countess assisted him in stopping the other Players. (PROSE: Endgame)