Richard Nelson Frye, The Harvard Theological Review, Vol. 55, No. 4 (Oct. 1962), pp. 261–268 https://www.jstor.org/pss/1508723 I use the term Iran in an historical context[...]Persia would be used for the modern state, more or less equivalent to "western Iran". I use the term "Greater Iran" to mean what I suspect most Classicists and ancient historians really mean by their use of Persia—that which was within the political boundaries of States ruled by Iranians.