Battle of Zaruthstra

The Battle of Zaruthstra was a conflict that took place in the year 4037. It is known that one side was an unidentified near-human species, Sontaran Commander Strax acted as a Nurse for this side, tending to soldiers from the battlefield. The Doctor's TARDIS landed here and summoned Strax, who owed him a debt, to help in his mission to rescue Amy Pond and her baby at Demons Run. (DW: A Good Man Goes to War)

Zaruthstra is likely the location, possibly planet, that the battle took place.