War Queen

You may be looking for the leader usually known by that title.

War Queen or War King was a title held by the leader of the Great Houses during the War. (PROSE: The Book of the War)

Thessalia said that the Imperator considered the title "War King" and, if he had been later, it would have been his chosen name. (PROSE: The Return of the King)

Six years before the War, a former renegade was declared War King on the Homeworld; he became known only as "the War King". Two years before the War (PROSE: The Book of the War) on another Gallifrey, Romana III was Lady President, War Queen, and Mistress of the Nine Gallifreys. (PROSE: The Shadows of Avalon)

More than fifty years into the War, Lolita consumed the War King and declared herself the new War Queen. (AUDIO: Words from Nine Divinities)