Atrios

Atrios was a planet devastated by nuclear war with its neighbour Zeos and ruled by a monarchy represented by Princess Astra. The war effort was led by the Marshal of Atrios.

The Planet of Evil blocked a view of Zeos from Atrios and vice versa. The Doctor destroyed the Planet of Evil by rerouting missiles fired by the marshal originally directed at Zeos. (DW: The Armageddon Factor)