Historically, the name Azerbaijan was used to refer to the region located south of the Aras River- today known as Iranian Azerbaijan, located in northwestern Iran. The region in the north of the Aras River, which is today called the Republic of Azerbaijan, had not been included within the geographical boundaries of Azerbaijan until 1918. Historians and geographers usually referred to the region north of the Aras River as Aran.On May 28, 1918, following the collapse of the Russian Empire, a group of political activists in Aran decided to change the name of their region to Azerbaijan by calling it Azerbaijan People’s Republic. Historians and scholars have argued that the Pan-Turkic agenda drove the name change.