CHRONOLOGY
This chronology has been compiled on the basis of a number of different criteria, ranging from the interpretation of ancient texts to the radiocarbon dating of excavated materials. The dates from 664 BC to AD 394 are precise, whereas those for prehistory (c.700,000-3000 BC) are approximations based on a combination of stratigraphic information, seriation of artefacts, radiocarbon dates, and the thermoluminescence dates.

The dates for the majority of the Pharaonic Period (i.e. c.3000-664 BC) are based mainly on ancient king-lists, dated inscriptions, and astronomical records. In the New Kingdom and Third Intermediate Period the margin of likely error is about a decade, but this tends to increase as we move further back in time, so that in the Old Kingdom it might be about fifty years, and in the 1st Dynasty it might be as high as 150 years. When the dates for two or more dynasties overlap (principally in the Second and Third Intermediate periods) it is because their rule was accepted in different parts of the country. Overlapping dates for reigns within dynasties usually indicate co-regencies. When there are apparent gaps in the chronology (particularly at the end of dynasties), this is usually because there are one or two extremely poorly documented rulers, whose regnal dates are unknown or difficult to assess.

By the beginning of the Old Kingdom, Egyptian rulers had five names; the oldest of these was the so-called Horus name, and this is the one that we have usually cited for kings of the 1st-3rd dynasties (except in the case of Djoser, whose Horns name, Netjerikhet, is given in parentheses). From the 4th Dynasty onwards, we have usually given one or both of the so called cartouche names (i.e. the 'nesu-bit' and 'son of Ra' names), and we have also sometimes added the Greek form of the name, especially when this is the name by which a ruler is better known to modern readers (e.g. Cheops for Khufu). Note that the existence and chronological position of the 3rd Dynasty ruler Nebka are currently a matter of debate.