Early Persia was a powerful empire, whose vast plateau surrounded by mountain ranges, was variously occupied by Arabs, Turks and Mongols.
The discovery of oil in the early 20th century created international game in the nation, especially England and Russia. A 1907 Anglo-Russian agreement divvied up Iran into spheres of influence, though it was later annulled after the First World War.
in 1935 the Iranian government requested those countries which it had diplomatic relations with, to call Persia "Iran," which is the name of the country in Persian.
The suggestion for the change is said to have come from the Iranian ambassador to Germany, who came under the influence of the Nazis. At the time Germany was in the grip of racial fever and cultivated good relations with nations of "Aryan" blood. It is said that some German friends of the ambassador persuaded him that, as with the advent of Reza Shah, Persia had turned a new leaf in its history and had freed itself from the pernicious influences of Britain and Russia. This would not only signal a new beginning and bring home to the world the new era in Iranian history, but would also signify the Aryan race of its population, as "Iran" is a cognate of "Aryan" and derived from it.