The inscriptions cover a space of at least a hundred and eighty years, commencing with Cyrus, and terminating with Artaxerxes Ochus, the successor of Mnemon.

The style of the writing is, on the whole, remarkably uniform, the latter inscriptions containing only two characters unknown to the earlier times.

Orthography, however, and grammar are in these later inscriptions greatly changed, the character of the changes being indicative of corruption and decline, unless, indeed, we are to ascribe them to mere ignorance on the part of the engravers.
There can be little doubt that, besides the cuneiform character, which was only suited for inscriptions, the Persians employed a cursive writing for common literary purposes.

Ctesias informs us that the royal archives were written on parchment; and there is abundant evidence that writing was an art perfectly familiar to the educated Persian.

It might have been supposed that the Pehlevi, as the lineal descendant of the Old Persian language, would have furnished valuable assistance towards solving the question of what character the Persians employed commonly; but the alphabetic type of the Pehlevi inscriptions is evidently Semitic; and it would thus seem that the old national modes of writing had been completely lost before the establishment by Ardeshir, son of Babek, of the new Persian Empire..