Carbon dating artefacts
By measuring the amount of carbon-14 in organic remains, scientists can determine how long ago they were living.
Radiocarbon dating has been used on Egyptian artefacts in the past, but the results were not accurate.
"For this reason we were not able to make measurements on current excavations, which would have helped a lot, particularly in improving the precision of the estimates for the Old and Middle Kingdoms.
They avoided using samples from wood or charcoal, due to their misleading nature.
They also avoided mummified remains, which might be contaminated by materials used in the mummification process.
The reign of king Djoser, who is credited with building the first pyramid, the Saqqara pyramid, is estimated through the study to have started between 26 BC. "It rules out the lower chronologies, which move the Old Kingdom later in time by about 50 to 100 years," said Ramsey.
The New Kingdom was much more precisely dated, and the research showed that the reigns of the kings of this period, including Tutankhamun, might actually have been about a decade earlier than previously thought.