In the third century B.C., a Greek-speaking Egyptian named Manetho compiled a comprehensive list of ancient Egypt’s pharaohs. Manetho served as a priest during the reigns of the first two Ptolemaic kings, Ptolemy I Soter (304–285 B.C.) and Ptolemy II Philadelphus (285–246 B.C.). In his book on the history of Egypt, called Aegyptiaca, Manetho grouped Egyptian pharaohs into 30 dynasties, a system we still use today.

As a priest, Manetho was literate (able to read not only Egyptian hieroglyphics but also Greek, the language of Aegyptiaca) and could gather information from temple libraries and inscriptions on temple walls, which sometimes recorded the names of kings and the number of years they reigned. Manetho probably also relied on traditional legends about the pharaohs.

The chronology Manetho provided in Aegyptiaca survives only in fragments quoted by other ancient writers. The earliest of these quotations are found in the works of Josephus, a late-first-century A.D. Jew from Jerusalem who wrote histories in Greek while living in Rome. Manetho’s Egyptian chronology is also quoted by the early third-century A.D. Christian historian Sextus Julius Africanus, the fourth-century bishop Eusebius, and the eighth-century historian George Syncellus.

These fragments, however, do not make up a reliable kinglist for Egyptian pharaohs; there are numerous gaps and many contradictions among the sources. What they do supply is a starting point, both for dating kings relative to one another and for grouping them into dynasties.