[Following the study I made on some points connected with chronological matters relating to the Sasanian period, I published some short articles dealing with these points in BSOS., ix, pp. 125–139, and ZMDG., vol. 91, part 3, pp. 675–7. In 1938 and 1939 I concluded these studies with an article on the chronology of the early Sasanian rulers for publication in BSOS.in 1939. The Bulletin being already completed for Press, the publication of my article was not found possible, and therefore Professor Sten Konow, of Oslo, on the suggestion of my old friend Professor Arthur Christensen, of Copenhagen, who is himself one of the best living authorities on the history of the Sasanian period of Iran, offered to publish the article in Acta Orientalia. Accordingly I sent the copy of the article to Oslo in the closing weeks of 1939. Professor Konow, in a letter which reached me in March, 1940, asked me if, owing to some difficulty in sending and getting back printed matter by ordinary post at that time, he could read the proof of the article himself and proceed to publish it. I agreed, but my reply to this effect, though sent immediately, did not reach him owing to the cessation of postal communication between England and Norway. I have never since been able to ascertain if the article was or was not published in the Acta.
In the meantime I have been pursuing my study of this subject, and new points occurring to me from time to time, I decided some time later to revise the whole article, and the following pages are the result, which may be considered as a fully revised form of the article which was to be published in the acta.]