The dynamic between the Central Empire and the Peripheral Empires constitutes an internal conflict in the Intermediate Region. Each of the main peoples in this area struggled to seize control of its centre of influence, that is, Byzantium-Constantinople-Istanbul, which remained the undisputed focal point for nearly 2000 years. The Arabs, in the 8th century, and the Russians, in the 20th century, almost succeeded in doing so but were not able to take control of the ecumenical empire.