Kafiristan

Kafiristan was a Middle Eastern country near the Soviet Union.

In 1990, Sayf Udeen was the prince of the country. It was invaded by the Metatraxi who were eventually defeated by the Seventh Doctor and Katie Tollinger. (DW: Crime of the Century)

Behind the scenes
Kafiristan ("land of the infidels") was a real historical region that became known as Nuristan("land of illumination") in 1895 and is now a province of Afghanistan.