The Mysterious Numbers of the Hebrew Kings

Edwin R. Thiele's The Mysterious Numbers of the Hebrew Kings (1951) is a reconstruction of the chronology of the kingdoms of Israel and Judah. The book was originally his doctoral dissertation and is widely regarded as the definitive work on the chronology of Hebrew kings. The book is considered the classic and comprehensive work in reckoning the accession of kings, calendars, and co-regencies, based on biblical and extra-biblical sources.

The chronology of the kings of Israel and Judah rests primarily on a series of reign lengths and cross references within the books of Kings and Chronicles, in which the accession of each king is dated in terms of the reign of his contemporary in either the southern Kingdom of Judah or the northern Kingdom of Israel, and fitting them into the chronology of other ancient civilizations.

However, some of the biblical cross references did not seem to match, so that a reign which is said to have lasted for 20 years results in a cross reference that would give a result of either 19 or 21 years. Thiele noticed that the cross references given during the long reign of King Asa of Judah had a cumulative error of 1 year for each succeeding reign of the kings of Israel: the first cross-reference resulted in an error of 1 year, the second gave an error of 2 years, the third of 3 years and so on. He explained this pattern as a result of two different methods of reckoning regnal years: the accession year method in one and the non-accession year method in the other. Under the accession year method, if a king died in the middle of a year, the period to the end of that year would be called the "accession year" and Year 1 of the new king's reign would begin at the new year. Under the non-accession year method the period to the end of the year would be Year 1 of the new king and Year 2 would begin at the start of the new year. Israel appears to have used the non-accession method, while Judah used the accession method until Athaliah seized power in Judah, when Israel's non-accession method appears to have been adopted in Judah.

In addition, Thiele also concluded that Israel counted years using the ecclesiastical new year starting in the spring month of Nisan, while Judah counted years using the civil year starting in the autumn month of Tishrei. The cumulative impact of differing new years and different methods of calculating reigns explained, to Thiele, most of the apparent inconsistencies in the cross references.

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