King lists and the stars are written evidence. Radiocarbon dating is a different kind: it reads a clock built into living things. It is especially useful for the times before writing, when there are no reigns to add up at all.
Key idea
Radiocarbon dating measures how much carbon-14 is left in plant or animal remains. It gives a range of years, often several decades wide, not one exact year. Studies of short-lived plant remains from well-dated Egyptian contexts largely agree with the standard chronology.
Why it works
Living things take in carbon from the air, including a tiny share of radioactive carbon-14. When they die, they stop taking it in, and the carbon-14 slowly decays: half of it is gone in about 5,700 years. Measuring what is left tells you how long ago the plant or animal died. Because the amount of carbon-14 in the air has varied, labs calibrate the result against tree rings, which turns it into a range of calendar years.
Choosing good samples
- Short-lived plants (seeds, reeds, linen) are best: they died in the same year they grew.
- Old wood can mislead: a beam might come from a tree that grew centuries before it was cut, or be reused.
- The sample must come from a context tied to a king, such as grain from a sealed tomb of known date.
A large study published in 2010 (Bronk Ramsey and colleagues) dated more than 200 such samples from the Old, Middle and New Kingdoms. The results fit the historians' chronology in broad outline, with some dates a little earlier than many had used. For the Predynastic Period and the first dynasties, radiocarbon is our main tool: it places the beginning of the 1st Dynasty around 3100–3000 BC.
Worked example: Reading a range
A lab reports a date of 1450 ± 40 BC for seeds from a tomb. What range of years does that cover?
- ± 40 means 40 years either side of 1450.
- Earliest: 1450 + 40 = 1490 BC (bigger BC numbers are earlier).
- Latest: 1450 − 40 = 1410 BC.
Answer: From about 1490 to 1410 BC, a range of 80 years.
Common mistake
Thinking radiocarbon gives one exact year. It gives a range, often several decades wide, and the range can be wider where the calibration curve is flat. For the New Kingdom, the king lists are usually more precise; radiocarbon is a check on them, not a replacement.