The chronology of ancient Egypt

The chronology of ancient Egypt can only be recovered (and then, inexactly) by combining several approaches. These include the sequences of kings and reigns, grouped into dynasties and larger periods. Original documents and interstate synchronisms (plus genealogical data) permit considerable control. To some extent, if their ambiguities can be overcome, lunar and 'Sothic' dates from astronomy can help. Other science-based techniques (e.g., radiocarbon) are not precise enough to help, except in the prehistoric epoch. The margin of error of c. 200 years in early third millennium BC sinks to 20/10 years during the second millennium, and to zero in 664 BC.