Age Pyramid Building Egypt Timeline Assignment


Archaeologists believe Egypt’s large pyramids are the work of the Old Kingdom society that rose to prominence in the Nile Valley after 3000 B.C. Historical analysis tells us that the Egyptians built the Giza Pyramids in a span of 85 years between 2589 and 2504 BC.

Interest in Egyptian chronology is widespread in both popular and scholarly circles. We wanted to use science to test the accepted historical dates of several Old Kingdom monuments.

Previous estimates

One radioactive, or unstable, carbon isotope is C14, which decays over time and therefore provides scientists with a kind of clock for measuring the age of organic material.

The earliest experiments in radiocarbon dating were done on ancient material from Egypt. Willard F. Libby’s team obtained acacia wood from the 3rd Dynasty Step Pyramid of Djoser to test a hypothesis they had developed.

Libby reasoned that since the half-life of C14 was 5568 years, the Djoser sample’s C14 concentration should be about 50% of the concentration found in living wood (for further details, see Arnold and Libby, 1949). The results proved their hypothesis correct.

Subsequent work with radiocarbon testing raised questions about the fluctuation of atmospheric C14 over time. Scientists have developed calibration techniques to adjust for these fluctuations.

What is radiocarbon dating?

All living things are built of carbon atoms. There are various isotopes, or species, of carbon atoms with the same atomic number but different mass.

One radioactive, or unstable, carbon isotope is C14, which decays over time and therefore provides scientists with a kind of clock for measuring the age of organic material.

While alive, all plants and animals take C14 into their bodies. The numbers of C14 atoms and non-radioactive carbon atoms remain approximately the same over time during the organism’s life. As soon as a plant or animal dies, the carbon uptake stops. The radioactive carbon isotope is no longer replenished; it only decays.

Scientists have calculated the rate at which C14 decays. By measuring how much C14 remains in a sample of organic material, we can estimate its age within a range of dates.

Samples older than 50,000 to 60,000 years are not useful for radiocarbon testing because by then, the amount of C14 remaining is too small to be dated. But material from the time of the pyramids lends itself well to radiocarbon dating because they fall into the 2575-1640 date range.

Radiocarbon technicians prefer to test wood and wood charcoal because their high molecular weight mitigates material loss during the rigorous pretreatments required for radiocarbon testing. We focused our collection efforts on tiny pieces of these materials, along with reed and straw left by the ancient builders.


Project members collect samples

In 1984 we conducted radiocarbon dating on material from Egyptian Old Kingdom monuments (financed by friends and supporters of the Edgar Cayce Foundation). We then compared our results with the mid-point dates of the kings to whom the monuments belonged (Cambridge Ancient History, 3rd ed.).

The average radiocarbon dates were 374 years earlier than expected.

In spite of this discrepancy, the radiocarbon dates confirmed that the Great Pyramid belonged to the historical era studied by Egyptologists.


In 1994-1995 the David H. Koch Foundation supported us for another round of radiocarbon dating.

We broadened our sampling to include material from:

  • The 1st Dynasty tombs at Saqqara (2920-2770 BC).
  • The Djoser pyramid (2630-2611 BC).
  • The Giza Pyramids (2551-2472BC).
  • A selection of 5th Dynasty pyramids (2465-2323 BC).
  • A selection of 6th Dynasty pyramids (2323-2150 BC).
  • A selection of Middle Kingdom pyramids (2040-1640 BC).

We also took samples from our Giza Plateau Mapping Project Lost City excavations (4th Dynasty), where we discovered two largely intact bakeries in 1991. Ancient baking left deposits of ash and charcoal, which are very useful for dating.

The 1995 set of radiocarbon dates tended to be 100 to 200 years older than the Cambridge Ancient History dates, which was about 200 years younger than our 1984 dates.

Comparison 1984/1995

The number of dates from the two projects was only large enough to allow for statistical comparisons for the pyramids of Djoser, Khufu, Khafre, and Menkaure.

There are two striking results.

First, there are significant discrepancies between the 1984 and 1995 dates for Khufu and Khafre, but not for Djoser and Menkaure.

Second, the 1995 dates vary widely even for a single monument. For Khufu’s Great Pyramid, they scatter over a range of about 400 years.

Date agreements

We have fair agreement for the 1st Dynasty tombs at North Saqqara between our historical dates, previous radiocarbon dates, and our radiocarbon dates on reed material.

We also have fair agreement between our radiocarbon dates and historical dates for the Middle Kingdom. Eight calibrated dates on straw from the pyramid of Senwosret II (1897-1878 BC) ranged from 103 years older to 78 years younger than the historical dates for his reign.

Four of the Senwosret II dates were only off by 30, 24, 14, and three years. Significantly, the older date was on charcoal (see “old-wood problem” below).

Test results from Middle Kingdom pyramid (Senwosret II).

The old-wood problem

Ancient Egypt’s population was restricted to the narrow confines of the Nile Valley with, we assume, a sparse cover of trees. It is likely that, by the pyramid age, the Egyptians had been intensively exploiting wood for fuel for a long time.

Because of the scarcity and expense of wood, the Egyptians would reuse pieces of wood as much as possible. Some of this recycled wood was burned, for example, in mortar preparation. If a piece of wood was already centuries old when it was burned, radiocarbon dates of the resulting charcoal would be centuries older than the mortar for which it was burned.

We thought that it was unlikely that the pyramid builders consistently used centuries-old wood as fuel in preparing mortar. The 1984 results left us with too little data to conclude that the historical chronology of the Old Kingdom was wrong by nearly 400 years, but we considered this at least a possibility.

Alternatively, if our radiocarbon estimations were in error for some reason, we had to assume that many other dates obtained from Egyptian materials were also suspect. This prompted the second, larger, 1995 study.

Old Kingdom problem

If the Middle Kingdom radiocarbon dates are good, why are the Old Kingdom radiocarbon dates from pyramids so problematic?

The pyramid builders often reused old cultural material, possibly out of expedience or to make a conscious connection between their pharaoh and his predecessors.

Beneath the 3rd Dynasty pyramid of pharaoh Djoser, early explorers found more than 40,000 stone vessels. These vessels included inscriptions of most of the kings of the 1st and 2nd Dynasties, but Djoser’s name occurred only once. Did Djoser gather and reuse vases that were already 200 years old from tombs at North Saqqara?

In the 12th Dynasty, Amenemhet I (1991-1962 BC) left clear evidence of this kind of recycling. He took pieces of Old Kingdom tomb chapels and pyramid temples (including those of the Giza Pyramids) and dumped them into the core of his pyramid at Lisht.

Test results from 5th Dynasty pyramid (Sahure).

Three of the eight radiocarbon dates from samples taken at our excavation at the Lost City are almost direct hits on Menkaure’s historical dates: 2532- 2504 BC. The other five range from 350 to 100 years older.

Our radiocarbon results from the Lost City site suggest that the dates on charcoal scatter widely, like those from the pyramids, with many dates older than the historical estimate. The inhabitants were very likely recycling their own settlement debris during the 85 or so years that they were building pyramids.


It may have been premature to dismiss the old wood problem in our 1984 study. Radiocarbon dating can only tell us when a tree died, not when it was last used. Wood may lay around for centuries before being burned, especially in a dry climate like Egypt.

Also, any living forest or stand of trees will have old trees and very young shoots. Any individual tree will have old parts (the inner rings) and very young parts (the outer rings and small branches).

Do our radiocarbon dates reflect the Old Kingdom deforestation of Egypt?

Did the pyramid builders exploit whatever wood they could harvest?

Or did they have to scavenge for wood to burn tons of gypsum for mortar, to forge copper chisels, and to bake bread for thousands of assembled laborers?

The giant stone pyramids in the early Old Kingdom may mark a major depletion of Egypt’s exploitable wood. This may be the reason for the wide scatter and history-unfriendly radiocarbon dating results from the Old Kingdom.

While the multiple old-wood effects make it difficult to obtain pinpoint age estimates of pyramids, the David H. Koch Pyramids Radiocarbon Project now has us thinking about forest ecologies, site formation processes, and ancient industry and its environmental impact—in sum, the society and economy that left the Egyptian pyramids as hallmarks for all later humanity.

The David H. Koch Pyramids Radiocarbon Project was a collaborative effort of Shawki Nakhla and Zahi Hawass, The Egyptian Supreme Council of Antiquities; Georges Bonani and Willy Wölfli, Institüt für Mittelenergiephysik, Eidgenossische Technische Hochschule; Herbert Haas, Desert Research Institute; Mark Lehner, The Oriental Institute and the Harvard Semitic Museum; Robert Wenke, University of Washington; John Nolan, University of Chicago; and Wilma Wetterstrom, Harvard Botanical Museum. The project was administered by Ancient Egypt Research Associates, Inc.

See also: Bonani G, Haas H, Hawass Z, Lehner M, Nakhla S, Nolan J, Wenke R, Wölfli W. “Radiocarbon Dates of Old and Middle Kingdom Monuments in Egypt,” Radiocarbon 43, No. 3 (2001), 1297-1320(24).

Egypt History Timeline

This page was last updated on April 7, 2017.

Prehistoric Egypt
  • (10,500 BC) wild grain harvesting began along the Nile River Delta
  • (8000 BC) humans began migrating to the Nile, developing a more centralized and settled society
  • (6000 BC) single-sailed row boats were depicted in Egyptian rock art
  • (4th millennium BC) Gerzean tomb-building began
3rd millennium BC
  • (3900 BC) increasingly dry conditions in the Sahara caused migration to the Nile Valley
  • (3100 BC) Upper and Lower Egypt unified by Pharaoh Narmer
  • (3100 BC) the early Dynastic Period began; hieroglyphics developed as a formal writing system
  • (3000 BC) Egyptians began to measure time based on a calendar of three natural cycles: the solar day, the lunar month, and the solar year
2nd millennium BC
  • (2890 BC) the second dynasty in Egypt founded by Hetepsekhemwy
  • (2800 BC) mining of the Sinai began
  • (2700 BC) papyrus, a thin paper-like material, was developed for writing on
  • (2660 BC) the first fortress on the Nile is built by Pharaoh Kasekhemwy following the unification of north and south Egypt
  • (2650 BC) the Step Pyramid at Saqqara was built for King Djoser, making it the first Egyptian pyramid
  • (2649 BC) the third dynasty is founded by Zanakht
  • (2575 BC) the Great Pyramids of Egypt were built in Dahshur and Giza; the 4th dynasty is founded by Sneferu
  • (2515 BC) the Sphinx is built for Khephren
  • (2465 BC) the 5th dynasty is founded by Userkhaf
  • (2184 BC) Egypt's Old Kingdom crumbled after the death of Pepi II
  • (2134 BC) Egypt is divided into the two smaller states of Memphis in the north and Thebes in the south
  • (2055 BC) the age of the Middle Kingdom began
  • (2040 BC) Nebhetepre Mentuhotep I reunited Egpyt, making Thebes the capital
  • (2000 BC) obelisks are constructed at Heliopolis
1st millennium BC
  • (1991 BC) Amenemhet I seized power during the 12th dynasty and moved the capital of Egypt to Ith-Tawy; the "Wall of the Prince" is erected in Sinai to protect Egypt from invasion
  • (1962 BC) Senusret I succeeded Amenemhet and expands the region; fortress were built at Semna and Kerma
  • (1640 BC) Hyksos, a Semitic people from Palestine, seized power in Northern Egypt along the Delta; horse-driven chariots are introduced
  • (1550 BC) the age of the New Kingdom began under the ruling of Ahmose I
  • (1532 BC) the Hyksos are defeated and expelled from Egypt by Ahmose I
  • (1525 BC) Ahmose I dies and is succeeded by Amenhotep I
  • (1504 BC) Tuthmosis I succeeded Amenhotep
  • (1492 BC) Tuthmosis became first pharaoh buried in the "Valley of the Kings"
  • (1458 BC) Tuthmosis III conquered Syria
  • (1450 BC) Egyptians began using the sundial
  • (1319 BC) Horemheb moved the capital back to Memphis
  • (1307 BC) Horemheb is succeeded by Ramesses I; the capital of Egypt moved to Avaris
  • (1300 BC) Egyptians build a canal connecting the Nile River and the Red Sea
600 BC - 0 AD
  • (669 BC) Egypt conquered by Assyrians and Mesopotamia
  • (332 BC) Alexander the Great invaded Egypt; the New Kingdom ended ushering in an era ruled by Greek Kings; the city of Alexandria is founded
  • (196 BC) the Rosetta Stone is carved in Greek and Egyptian
  • (51 BC) Cleopatra VII becomes queen Egypt
  • (31 BC) Greek ruling of Egypt ended after the Roman conquest
100s AD - 1800s
  • (250 AD) Diophantus wrote "Arithmetica" on algebraic equations and the theory of numbers
  • (394 AD) the last hieroglyph is inscribed at Philae
  • (641 AD) Arabs conquered Egypt, ending Roman rule; Egyptians converted to Islam
  • (642 AD) the library of Alexandria is destroyed
  • (969 AD) Cairo established as capital of Egypt
  • (1517) Egypt is absorbed into the Ottoman Empire
  • (1859) construction began on the Suez Canal
  • (1869) Suez Canal is completed
  • (1882) British troops invaded Egypt


  • (1914) Egypt became a British protectorate
  • (1922) Egypt gained independence; Faud I becomes king
  • (1928) the Muslim Brotherhood is founded
  • (1948) Egypt, along with Iraq, Jordan, and Syria attacked the new state of Israel
  • (1952) anti-British riots erupted in Cairo, at least 20 killed
  • (1953) Muhammad Najib staged coup; Egypt declared a republic with Najib as president
  • (1954) Gamal Abdel Nasser becomes prime minister; remaining British forces vacated
  • (1956) Egypt invaded by Britain, France, and Israel following the nationalization of Suez Canal, a ceasefire is issued one month later
  • (1958) Egypt and Syria joined to form the United Arab Republic (UAR)
  • (1961) Syria withdrew from UAR union with Egypt; Egypt remained as the UAR
  • (1967) Egypt and Jordan signed defense pact
  • (1967) six day war began with Egypt, Israel, Jordan, and Syria; Israel gained control of Sinai, Golan Heights, the Gaza Strip, East Jerusalem, and the West Bank
  • (1970) Anwar al-Sadat became president following the death of Nasser
  • (1971) Egypt and the Soviet Union signed a Treaty of Friendship
  • (1971) a new constitution is introduced; Egypt is renamed the Arab Republic of Egypt
  • (1971) the Aswan High Dam is completed
  • (1975) the Suez Canal is reopened after its closure during the six day war in 1967
  • (1976) the Treaty of Friendship with the Soviet Union is ended
  • (1978) a peace treaty with Israel is signed
  • (1981) Anwar al-Sadat is assassinated; Hosni Mubarak is assigned president
  • (1989) Egypt rejoined the Arab League
  • (1997) 58 tourists are killed by gunmen from Egypt's Islamic Group (al-jama'ah al'islamiyah)
  • (1999) Mubarak entered his 4th term in office
  • (2000) an agreement between Egypt, Lebanon, and Syria is reached for a pipeline to carry Egyptian gas under the Mediterranean to Tripoli
  • (2004) Israeli tourists attacked on Sinai peninsula, 34 people are killed
  • (2005) anti-government activists stage demonstrations
  • (2005) a constitutional amendment allowing multiple candidates in presidential elections is backed by a referendum vote
  • (2005) clashes between police and opposers of the Muslim Brotherhood erupted following the Parliamentary polls
  • (2006) a ferry carrying 1,400 passengers from Saudi Arabia to Egypt sinks in the Red Sea killing nearly 1,000 people
  • (2011) Egyptians staged nationwide demonstrations against President Mubarak; Mubarak stepped down amidst protests, turning power over to the military; the parliament is dissolved and the constitution is suspended
  • (2012) new parliamentary and presidential elections are held; Mohamed Morsi is elected president
  • (2012) Morsi granted himself greater power and immunity; widespread protests reignited
  • (2013) a period of civil unrest continued with mass protesting; Morsi is deposed of in a coup headed by Abdul Fatah al-Sisi and the Egyptian armed forces on July 3rd, and is replaced by the chief justice of the Supreme Constitutional Court
  • (2013) a month-long state of emergency is declared across Egypt amidst widespread and bloodied protests
  • (2014) a new constitution (prepared in 2013) was enacted on January 18th after a 98% approval of the people's votes; presidential and parliamentary elections are expected to be held in the following 6-months
  • (2014) Morsi's supporters were sentenced to death; Morsi's own trial remained ongoing as of March 24th

Egypt's Information

Land Area995,450 km2
Water Area6,000 km2
Total Area1,001,450km2 (#29)
Population94,666,993 (#15)
Population Density95.10/km2
Government TypePresidential Republic
GDP (PPP)$1,110.00 Billion
GDP Per Capita12,100$
CurrencyPound (EGP)
More InformationEgypt

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