Goritania
From Tardis Wiki, the free Doctor Who reference
Goritania was a country of which Rudolph was the crown prince in the 1780s.
The Tenth Doctor had never heard of it and found it difficult to find. This was due to a Mefistole bargain. This bargain made the country completly invisible. Due to it being invisible Goritania has not had a war in 500 years at the time of Death and the Queen. (AUDIO: Death and the Queen)