Why Ussher’s Chronology is Wrong
In 1650, James Ussher published Annales Veteris Testamenti, a chronology of the Old Testament. In it, he claimed that the first day of creation was October 22, 4004 BC. Although this represented skillful work and much effort, we now know that he was working with faulty data and a simple lack of information.
Ussher addressed biblical chronology in three major sections, which are still useful today: the monarchy (Solomon to Zedekiah), Abraham to David, and creation to Abraham. He was even able to anchor the end of the monarchical period on a date that is still considered reliable today–the accession of Amel-Marduk (Evil-merodach) in the 37th year of the exile of Jehoiachin, known to have occurred in 562 BC. However, that remains the only date either used or calculated by Ussher that was precisely correct.
Monarchy. Thanks to the work of Edwin Thiele, we now understand that the regnal data for the kings of Israel and Judah was accurately preserved in the Hebrew Bible. However, it is beautifully complex, and to comprehend how it works one must be aware of: 1) the two different calendars that were used in the Iron Age [one beginning in the month of Nisan and the other in Tishri]; 2) the two systems used to count years of rule [the accession year and non-accession year systems]; and 3) the existence of occasional co-regencies, where two kings had overlapping reigns. No one had put these three pieces together prior to Thiele, and thus no one was able to calculate accurate reign lengths for the kings of Israel and Judah. In fact, this complex system had not been understood for over 2,000 years. We know this because the Jewish scribes who translated the Hebrew Bible into Greek in the 3rd and 2nd centuries BC tried to adjust the numbers so that they would actually work (and ended up creating a greater mess). Ussher guessed at some of the co-regencies, but ultimately he had to pick and choose numbers (while ignoring “problem” texts) to make his system work, and he was simply unaware that two different calendars were used or that years were variously counted using the accession or non-accession year systems. As a result, he proposed that Solomon began construction on the temple in 1012 BC, whereas we now know that the correct date is 965 BC. Two examples of specific blunders made by Ussher are listed at the end of this post.
Abraham to David. This period is not so complex when it comes to working out a chronology (see here), but there is still room for the chronologist to make errors. One of the decisions Ussher made in working out dates for this period was to accept the LXX reading against the Hebrew Bible in 1 Kings 6:1 (it is notable that he does not follow the numbers given in the LXX in most other cases). As a result, he assigned only 215 years to the sojourn in Egypt (rather than the 430 given in the Hebrew Bible). This explains, at least in part, why he came up so short on the date for the birth of Abraham, placing it in 1996 BC rather than 2165 BC.
Creation to Abraham. Calculations for this period have the potential to provide an actual date for Creation. However, immediate skepticism comes from the fact that even within ancient Judaism there were multiple schemes, long before Ussher’s work. At least part of this is due to the vastly different genealogical numbers found in the Hebrew Bible vs. the LXX. As just one minor example, the Hebrew Bible states that Seth was 105 years old when Enosh was born, but the LXX gives 205 years. As a result of these difference, by simple addition the Hebrew Bible gives 1,656 years between Creation and the Flood, whereas the LXX gives 2,242 years. Ussher generally used the time-spans of the Hebrew Bible here, so it is no surprise that he does not account for Cainan between Shelah and Arphachsad (cf. Luke 3:36). There are other issues as well. For example, Gen 11:26 states that Nahor became the father of Abram, Nahor, and Haran when Nahor was 70 years old. However, Ussher deduced that Terah, who lived to 205 years, died before Abram migrated to Canaan at age 75, and thus he inserted a 60-year span between the births of Nahor and Haran and the birth of Abram.
Great advances in the study of biblical chronology have been made since the 17th century. Thiele’s work (The Mysterious Numbers of the Hebrew Kings, 1951) provided the key to finally solving a riddle that had stumped the brightest minds for centuries, and small tweaks and corrections have continued to refine this understanding. Even the chronology of the Judges period, once thought to be intractable, may now have a solution.
Given the large number of errors and incorrect assumptions that are woven throughout Ussher’s chronology (see the detailed article by James Barr), one might be surprised to learn that it is still followed in some circles today. Regrettably, Answers in Genesis still touts it as a reliable system (see here and here), perhaps for the simple reason that it supports a young age for the earth. However, most young-earth creationists do not follow Ussher’s chronology, nor is it in any way necessary to a young-earth view.
Specific examples of Ussher’s miscalculations
As noted above, Ussher was forced to pick and choose among various chronological statements, especially in the period of the monarchy, because they appeared to be irreconcilable. An example is the start of the reign of the Israelite king Jehoram. 2 Kings 3:1 states that Jehoram came to the throne “in the eighteenth year of Jehoshaphat king of Judah, and reigned twelve years.” However, 2 Kings 1:17 states that Jehoram came to the throne “in the second year of Jehoram the son of Jehoshaphat, king of Judah.” Ussher accepted the former statement (Annals, p88) and ignored the second. Thiele, however, perceived that there was a five-year co-regency between Jehoshaphat and Jehoram, and thus both statements were actually true.
Another example is the Israelite king Ahaziah, the father of Jehoram. 1 Kings 22:51 states that “he reigned two years over Israel.” Ussher struggled with this, because the verse also states that he came to the throne in the 17th year of Jehoshaphat, king of Judah, but 2 Kings 3:1 states that his son Jehoram came to the throne in the 18th year of Jehoshaphat, which would be less than two years. Ussher’s misguided suggestion was that Ahaziah “reigned two years, partly with his father, partly by himself” (Annals, p88). Its not a bad suggestion, really, but its wrong. What Thiele discerned was that the scribe who assigned two years to Ahaziah was using the non-accession system of counting reign lengths: Ahaziah came to the throne during late 853 BC, and died roughly a year later, sometime during 852 BC. However, in a non-accession system, the initial partial year of reign counts as year one, and the final partial year of reign was counted as a year of reign in any system, so it was proper for the scribe to list his rule as “two years,” even though it amounted to less than 24 months, and may have been closer to 12 months.
Dozens of examples like this could be given. Many of these issues are relatively small by themselves, but they add up to large discrepancies over the reigns of many kings.