Ancient Egypt, Radiocarbon Dating, and Bayesian Probabilities, P. SALATI (LAPTh/USMB) – October 3rd 2025 @2pm

Unlike the Maya, the Egyptians did not have an absolute calendar. They measured time relative to the start of the current pharaoh’s reign. This is why the absolute chronology of ancient Egypt remains largely unknown to this day. To attempt to determine it, the Meryt project, led by Anita Quiles, combines Bayesian analysis and radiocarbon (C14) dating. After a brief overview of the ancient Egyptians’ conception of time, I will explain the principle of C14 dating. I will then show how Bayes’ theorem naturally comes into play. The end date of Khufu’s reign will be used as an example, and we will step-by-step construct the statistical model to determine it based on C14 dating from the Wadi al-Jarf site.

Tablets or inscriptions discovered in excavations, which attest to events that took place, only indicate the royal census year of those events, to the nearest year. These records can be used alongside C14 dating to constrain the duration of each reign—that is, the period from its beginning to its end. I will explain the statistical method developed within the Meryt project to achieve this goal. We will then apply it to find the most probable duration of Khufu’s reign. Records and C14 dating can ideally be combined to obtain the most precise absolute chronology of ancient Egypt possible.

The seminar will be conducted in French.