I have always been interested in chronology, perhaps because it promises to apply some numerical rigour to ancient history. Sadly, things are rarely that simple. I thoroughly enjoyed Peter Jones' Centuries of Darkness, but ultimately found its proposal of a radical reform of ancient chronology to be unconvincing. But from time to time, I like to see how the chronological debates in ancient near eastern history (“ANE”) have progressed. The answer is usually, not by very much.
The problem with chronology is the need to pin an absolute date to relative dates. For example, if we have a list of kings of Assyria and how long they all reigned, we have a relative chronology for the Assyrians. If we also have references to the Assyrians sacking an Israelite city in the biblical records, we can pin the Assyrian chronology to the Hebrew one. And if an Egyptian pharaoh marched around Judea and this is recorded both in Egypt and the Bible, then we can attach the chronology of Egypt to our scheme as well. But we also need an absolute date so we can say exactly when a specified event happened. We can then extrapolate all our relative dates from this single absolute date to get an absolute chronology.
And herein lies the problem. Carbon 14 dates are nothing like accurate enough to provide absolute dates. The best that we can hope for is plus or minus thirty years, but there are serious doubts that the technique provides even this level of accuracy. Dendrochronology, dating from tree rings, can give you an absolute date for the year in which a tree was felled, but you cannot easily tie this to a historical event.
In fact, there is only one absolute date that everyone agrees with before the classical period. This is a total eclipse of the sun that took place on 14 June 763BC. NASA helpfully provides a map showing the path of the eclipse moving right across the Middle East (as well as a catalogue of all eclipses). Assyrian records note this eclipse in the 9th year of the reign of King Ashur-dan III. This ties all the ANE chronologies together, at least for the first half of the first millennium BC.
For chronology before 1000BC, things get complicated. Absolute dates have to be derived from observations about the rise of the star Sirius (Sothic dating used in Egypt) or the visibility of Venus (used in Babylon). But neither of these provides a single accurate date. For instance, the observations of Venus that tie to the reign of Hammurabi of Babylon occur every 60 years or so, which means that high, middle and low chronologies (with about 120 years between them) can all be argued for.
These problems could largely be solved if it was possible to date the Thera volcanic eruption that devastated large parts of the Mediterranean basin. Traditionally, this was believed to have happened shortly after 1500BC, but carbon dating and dendrochronology suggested a date of 1627BC. Evidence for the ash and pumice that the volcano ejected is laminated all over Asia Minor but, remarkably, the eruption is not recorded in any surviving records. Worse, it doesn’t even show up in the Greenland ice cores, where it should be very obvious. A likely candidate in 1642BC turns out to have been an eruption in Alaska. Quite why traces of the 60 cubic kilometres of rock ejected from Santorini do not stick out like a sore thumb or feature in any Egyptian records is odd to say the least.
So it seems by dreams of mathematical precision in the field of ancient chronology have been dashed. This probably won’t change until someone figures out how to precisely date the Thera eruption or new eclipse records turn up.
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