The Bactrian language (a Middle Iranian language) inscription of Kanishka the Great, the founder of the Kushan Empire at Rabatak, which was discovered in 1993 in an unexcavated site in the Afghanistan province of Baghlan, clearly refers to this Eastern Iranian language as Arya. In the post-Islamic era one can still see a clear usage of the term Aryan (Iran) in the work of the 10th-century historian Hamzah al-Isfahani. In his famous book "The History of Prophets and Kings", al-Isfahani writes, "Aryan which is also called Pars is in the middle of these countries and these six countries surround it because the South East is in the hands China, the North of the Turks, the middle South is India, the middle North is Rome, and the South West and the North West is the Sudan and Berber lands". All this evidence shows that the name arya "Iranian" was a collective definition, denoting peoples (Geiger, pp. 167 f. ; Schmitt, 1978, p. 31) who were aware of belonging to the one ethnic stock, speaking a common language, and having a religious tradition that centered on the cult of Ahura Mazdā.