Trion Civil War
From Tardis Wiki, the free Doctor Who reference
The Trion Civil War was a conflict on the planet Trion around the 20th century.
Turlough's family was on the losing side of the war. His mother was killed during the fighting. Turlough was exiled to Earth, whilst his younger brother Malkon and his father were sent to Sarn. By the time Turlough was reunited with his brother in 1984, an amnesty for former combatants in the civil war had been declared, allowing the siblings to return to their homeworld. (TV: Planet of Fire)