Fixing the chronology in Tai-Ahom chronicles by using astronomical references

Abstract

The Tai-Ahom are an ethnic group, the admixed descendants of the Tai or Shan people who migrated from North Burma into the Brahmaputra Valley of Assam in India in the early decades of the thirteenth century. Their history is meticulously documented in chronicles called buranjis, manuscripts written in the Ahom or Assamese language. The Ahom Buranji (Royal Chronicle) was first translated in 1930 and covers Ahom history from the earliest times until the end of the Ahom rule in 1826 CE. Another buranji translated into English is the Tungkhungia Buranji, which covers the period 1681–1826 CE. Sprinkled throughout these texts are references to solar and lunar eclipses and bright comets. These objects and events can be dated. Of particular interest in the Ahom Buranji is the record of an unusual occurrence during the reign of King Chao Susenpha, when the day suddenly became as dark as night. This had been identified as the solar eclipse of 6 March 1486 and was seen as an independent corroboration of the chronology in the Ahom Buranji. However, we find that this was a partial eclipse and was not visible over Assam. Instead, we found there was a total eclipse visible from Assam two years later, on 9 July 1488 CE. There is another solar eclipse mentioned in the Ahom Buranji, which we identified as that of 30 December 1758 CE. There are also two lunar eclipses on record, most likely those of 27 July 1646 and 4 February 1776 CE. Comets mentioned in the buranjis turned out to be the Great Comet of 1577, Chéseaux’s Comet of 1744, Halley’s Comet of 1759 and Messier’s Comet of 1769 CE. Since the dates of these astronomical events are precise, we have a larger dataset that can now be used to establish dates in Ahom history more exactly.