The question of finding a route between the Oxus valley and India has been of concern historically. A direct route crosses extremely high mountain passes in the Hindu Kush and isolated areas like Kafiristan. Some in Britain feared that the Empire of Russia, which at the time wielded great influence over the Oxus area, would overcome these obstacles and find a suitable route through which to invade British India – but this never came to pass. The area was taken over by Russia during the Russian conquest of Turkestan.