9. The eclipse
One avenue to the absolute dating of the Eponym List begins with a report of a solar eclipse in the year of eponym Bur-Saggile. His name is preserved on four of the Eponym List tablets, and two of the Lists mention the eclipse. Hand copies of the text indicate his name is legible on the four tablets.
The significance of the eclipse report was first noted in the middle of the 19th century, and a date for the eclipse was soon worked out.
10. The date
Dating the eclipse involved figuring out a rough date for Bur-Saggile around 760 BC, and then bringing astronomy to bear. According to conventional calculations, only two major eclipses were seen in Assyria between 777 and 745 BC. They are dated Feb 10, 765 and Jun 15, 763 BC. The eclipse report places the eclipse in the month of siwan, which corresponds to May/June and rules out the eclipse of Feb 10. Hence Bur-Saggile served as eponym in 763 BC. By this reckoning, the Eponym List spans the years 910-649 BC.
11. More Date
This absolute dating based on a single eclipse report can hardly be considered firm. Even so, many documents have come to light since the 19th century, and the dates of the Eponym List no longer rely solely on eclipse charts.
12. Super granny
In 1956 an archaeologist working on the ruins of a mosque turned over a paving stone and discovered a cuneiform treasure. The inscription tells the story of Adad-guppi, mother of King Nabonidus of Babylonia. She lived 104 years and must have had chronologists in mind when writing her biography.
From her birth in the 20th year of Assurbanipal, super-granny gives the length of every king's reign she lived through: Assurbanipal's 42nd year, Assur-etillu-ili's 3rd, Nabopolassar's 21st, Nebuchadnezzar's 43rd, Awel-Marduk's 2nd and Neriglissar's 4th - a total of 95 years.
13. More Super granny
Taking 568/67 BC as the astronomically determined date of Nebuchadnezzar's 37th year [See Feat of Clay], Adad-guppi's numbers spot the beginning of Assurbanipal's reign in 670 BC [567+37+21+3+42]. The conventional date for his accession year is 668 BC. The difference of two years may arise from inconsistencies in granny Adad-guppi's biography.