The Persians have a book called the _Kohan Nameh_ in which are mentioned all the officers of the Persian monarch amounting to 600 and classed according to their respective ranks. This book formed part of the _Ain Nameh._[1] The meaning of Ain Nameh is the 'Book of regulations'. It is a book containing several thousands of leaves and no one can find a copy of it anywhere except among the _mobeds_ and others invested with authority. The mobed of the Persians at the moment of writing this history, that is in the year 364, for the country of Jabal in Iraq and for the countries of Ajam, is Ammad son of Ashwahisht. Before him these countries had for their mobed Isfandiyar, son of Adarbad, son of Anmid, who was killed by Radi at Baghdad in 325. [Footnote 1: A remarkable passage from this Pahlavi treatise has been embodied in a close Arabic version in Ibn Kutayha's _Uyun-al-Akhbar._ The credit of discovering and translating this unique passage into a European language belongs to M.K. Inostranzev.] I have seen in the city of Istakhar in Fars in the year 303 in the house of a high noble Persian, a large book in which were set out along with the descriptions of several sciences the histories of the kings of Persia, their reigns and the monuments which they had erected,--fragments which I have not been able to find anywhere else in Persian books, neither in the _Khoday Nameh_, nor in the _Ain Nameh_ nor in the _Kohan Nameh_ or anywhere else. [Sidenote: Portrait of Sasanian kings taken just before their demise.] [Sidenote: Persian Imperial archives: Translation into Arabic.]