Egyptian chronology

Overview

The general outline of the conventional chronology has remained stable for about a century, though the Old Kingdom dates can vary by a few centuries. All dates in the table are approximate and in BC. Disparities arise from new discoveries and better understanding of incomplete evidence; for instance, Breasted included a Twentieth Dynasty ruler later shown not to exist, and he assumed all dynasties were sequential, whereas some are now known to be contemporary. These revisions have lowered the conventional chronology by up to 400 years at the start of Dynasty I.

Regnal years

Regnal years recorded in ancient Egyptian king lists form the backbone of the chronology. Surviving lists are either comprehensive but have gaps, like the Turin King List, or are textually complete but lack a full roster of rulers, such as the Abydos King List and the Palermo Stone. Conflicting information on the same regnal period appears in different versions of the same text; Manetho's history is known only through epitomes by Eusebius and Sextus Julius Africanus, and reign lengths for the same pharaoh often vary substantially.

Regnal periods are reconstructed from inscriptions that give a date in the regnal year of the ruling pharaoh, but this provides only a minimum length and may not account for coregencies. Some dynasties probably overlapped, with different pharaohs ruling simultaneously in different regions, and uncertainty about whether monarchies were simultaneous or sequential leads to widely differing chronological interpretations. Where total regnal years are unknown, Egyptologists use cattle censuses for the Old Kingdom and Sed festivals for later periods.

Old Kingdom inscriptions refer to a periodic cattle census once thought to occur every second year, so 24 censuses suggested Sneferu reigned 48 years, but later research showed censuses could be consecutive or spaced by more than two years. The Sed festival was usually celebrated on the thirtieth anniversary of a pharaoh's ascension, implying a reign of at least 30 years, though this may not have been standard practice in all cases.

Synchronisms

Chronological synchronisms help work around gaps in knowledge and can yield precise dates. Seriation, or archaeological sequences, does not fix a person or event to a specific year but provides indirect evidence; for example, inscribed stone vessels of first two dynasty rulers were deposited in storage galleries beneath the Step Pyramid of Djoser of the Third Dynasty, and Old Kingdom blocks bearing several kings' names were reused in Middle Kingdom pyramid-temples at Lisht built by Amenemhat I. The third pylon at Karnak, built by Amenhotep III, contained fill material from the kiosk of Sesostris I and stelae of the Second Intermediate Period and the Eighteenth Dynasty.

Synchronisms with other chronologies, especially Assyrian and Babylonian, but also Hittite, ancient Palestine, and ancient Greece, are used. The earliest such synchronism is from the 18th century BC: a stela of the governor of Byblos Yantinu indicates pharaoh Neferhotep I was contemporary with kings Zimri-Lim of Mari and Hammurabi of Babylon. Other early synchronisms date to the 15th century BC during the Amarna Period, when diplomatic correspondence exists between Egyptian Kings Amenhotep III and Akhenaten (or possibly Smenkhkare) and various Near Eastern monarchs.

For the Third Intermediate Period, Shoshenq I has been dated relative to Rehoboam and the Eponym dating system by Kenneth Kitchen, based on biblical passages about Shishak's campaign, with the absolute date calculated from Edwin R. Thiele's theory. Synchronisms with Apis bull interment memorials begin as early as Amenhotep III and continue into Ptolemaic times, but there is a significant gap between Ramesses XI and the 23rd year of Osorkon II. Poor documentation of these finds by Auguste Mariette at the Serapeum of Saqqara has compounded difficulties, though his notebooks are now available.

Alternative chronologies

Several alternatives to the conventional chronology were proposed during the 20th century. These include Immanuel Velikovsky's Revised Chronology in his Ages in Chaos series, Donovan Courville's chronology in The Exodus Problem and Its Ramifications, the Glasgow Chronology formulated in 1978 by members of Velikovsky's Society for Interdisciplinary Studies, the Centuries of Darkness model by Peter James et al. from 1991, and David Rohl's New Chronology described in his Test of Time series.