The purpose of this Symposium being to discuss ‘The impact of the natural sciences on archaeology’, I feel I am laying myself open to the criticism that the subject of my paper is putting the proper order into reverse, for I cannot pretend that 14 C has yet made any actual impact on our reconstruction of Egyptian chronology. If therefore, in the present context, my line of approach seems a little devious perhaps I may seek refuge in a claim made by the late Professor Maynard Keynes at a meeting which I attended at Cambridge many years ago. After listening to a distinguished French economist contending that the methods of procedure of his English colleagues were more logical than those of his French confreres, Keynes retorted: ‘We in England like to think that we arrive at a logical conclusion by a process which often seems illogical’. My excuse for speaking about what, in effect, is the assistance which Egypt can give to 14 C investigation is that this is something which Professor Libby has recognized as important from the very beginning of his work in that field and he himself has done his best to mobilize it. The reasons are twofold: ( a ) no other ancient civilization has left so large and varied a quantity of physically suitable material, and ( b ) it is generally possible to find Egyptian specimens, the age of which can be determined by other means than by 14 C measurement. It is with these other means of dating that I shall now deal. The ancient Egyptians, from very early times, employed three calendars, two mainly for religious purposes and the third for administrative and economic purposes, and for numbering the years of a king’s reign. The religious calendars were lunar in character and offer little help in determining absolute dating. It is the third— the so-called civil calendar—which is of importance for chronological purposes.