Chronology of Babylon and Persia

Ptolemy's Canon is one of the most important bases for our knowledge of Mesopotamia's ancient chronology. The Canon's increments by whole ancient Egyptian years (365 days per year) have two consequences. The first is that the beginning and ending dates of kings are simplified to the beginning and ending times of ancient Egyptian years, which are off about one day every four years against the Julian calendar. The second is that this list of kings is oversimplified: Kings who reigned for less than one year were not listed. Usually the overlapping year was assigned to the king who died in that year, but not always. The Canon is generally considered by historians to be quite accurate (probably with an error of less than 2 years) but is not the ultimate source for chronology synchronization. Here, we will make a revision on the Canon that only covers the kings from Nabopolassar to Darius III Codomannus, based on the detailed regnal lengths of the kings, which were summarized in Babylonian Chronology 626 B.C. –A.D.75 by Richard A. Parker and Waldo H. Dubberstein (Wipf and Stock Publishers, 2007).

Table IV lists the actual starting and ending dates of the kings. The overlapped time of two adjacent kings was due to coregency. The coregency between Cyrus and his son Cambyses II should have begun from Nisannu 1 of the 9^th year of Cyrus, according to a contract tablet which reads: "year 1, ascension year, Cambyses king of Babylon and Lands." [Kriickmann, Neubabylonische Rechts und Venoaltungstexte (Leipzig, 1933), No. 92]. Year 1 and the ascension year were the same year only if the king started to reign exactly on the first day of a new year (Nisannu 1). The astronomical clay tablet of BM 33066 records two lunar eclipses in July of 523 BC and in January of 522 BC, which was in the 7^th year of Cambyses II. This important astronomical record leads us to set the beginning date of the first year (or ascension year) of Cambyses II to be on Nisannu 1 (April 12) of 528 BC. Since the 9^th year of Cyrus was also on Nisannu 1 of 528 BC, the first year of Cyrus must have started on Nisannu 1 of 537 BC, and his ascension date should have been on the third day of the 8^th month of 538 BC when he took Babylon. This is one year later than the date generally accepted by historians. The previous Canon contradicts the fact that Cambyses II started to co-reign with his father exactly in the beginning of the new year. The second contradiction is that Labaši-Marduk should have reigned for at least 1 year and 3 months. Any king who reigned for less than one year should not have been in the Uruk King's List. But Labaši-Marduk is in the List and the text of the List contains a lacuna, where one should expect to read a year number for his reign. Therefore, Labaši-Marduk should have reigned for more than one year, in agreement with the modified chronology in Table IV.

The current chronology is also consistent with the third book of Chaldean history by Berosus, as reiterated by Josephus in Against Apion, bk. 1, 146-153. The added total regnal length for Neriglissar and Labashi-Marduk was 4 years and 9 months according to Josephus, which was in agreement with the current chronology (see Table IV).

The current chronology is further confirmed by the list of the Kings of Tyre (Table V), which is taken from <https://en.wikipedia.org/wiki/King_of_Tyre>. The list was constructed from Against Apion: bk. 1, 156-158. Josephus stated that Cyrus the Persian took the Babylonian kingdom in the fourteenth year of Hiram (Against Apion: bk. 1, 159). Since the 14^th year of Hiram was between the spring of 538 BC and the spring of 537 BC according to Table V, the third day of the 8^th month of 538 BC (when Cyrus took Babylon) was indeed in the 14^th year of Hiram. This excellent consistency suggests that our current chronology of Babylon and Persia is more accurate than the generally accepted one.