https://allthatsinteresting.com/when-was-the-great-pyramid-of-giza-built
New Analysis Suggests That The Great Pyramid Of Giza Is Potentially 20,000 Years Older Than Experts Thought
Published February 3, 2026
A new method that compares points of erosion on the
Great Pyramid of Giza suggests that this iconic monument could have been
constructed as early as 23000 B.C.E. — 20,000 years earlier than
previously believed.
Cornell University LibraryThe
Great Pyramid of Giza and the Great Sphinx, pictured here in the late
19th century. New research purports to upend established theories about
when the Great Pyramid of Giza was built.
The Great Pyramid of Giza, generally believed to have been built as the tomb of Pharaoh Khufu around 2575 B.C.E., is one of the Seven Wonders of the Ancient World. But what if it’s even older than that?
Alberto Donini, an engineer from the University of Bologna, recently
applied a new dating system that he calls the “Relative Erosion Method”
(REM) to the pyramid. Now, he’s claiming that his research suggests the
famous landmark may have actually been built nearly 25,000 years ago.
When Was The Great Pyramid Of Giza Built? The Origins Of Egypt’s Ancient Wonder
Scientific studies of the pyramids at Giza have been ongoing for
centuries, so the current timeline of their construction is widely
accepted. As it stands, the Great Pyramid was seemingly built during the
reign of Pharaoh Khufu, who ruled over Egypt from roughly 2589 B.C.E.
to 2566 B.C.E. The Pyramid of Khafre came shortly thereafter, followed
by the Pyramid of Menkaure.
This timeline was determined using both historical records and
scientific study. Ancient authors like Herodotus wrote that Khufu had
the Great Pyramid constructed as his tomb, noting that he “brought the
people to utter misery” by making them transport impossibly heavy
limestone blocks from quarries — possibly located hundreds of miles away
— in order to erect the 481-foot structure. Exactly how they managed this remains a mystery to this day, though several promising theories have been put forth, such as the use of a ramp system.
Public DomainA statue of Khufu at Cairo’s Egyptian Museum.
Then, in the 1800s, archaeologists discovered graffiti inside the
Great Pyramid that mentioned Khufu by name. It was seemingly scrawled by
the workers who built the monument, adding another layer of evidence that the structure was built during that pharaoh’s reign.
Archaeologists later used scientific methods to date the pyramid.
They radiocarbon dated the mortar used to secure the stone blocks, which
was made using ashes and thus contained organic matter. These results
suggested that the mortar was likely mixed between 2620 and 2484 B.C.E.,
once again aligning with the reign of Khufu.
With so much proof pointing to a construction date of roughly 2575 B.C.E.,
it seems unlikely that there’s any additional information out there
that could significantly change the timeline. However, Alberto Donini
claims that his research could completely rewrite this story.
Why The Relative Erosion Method Could Complicate The Story Of How Old The Great Pyramid Of Giza Is
In a preliminary report
on his research, Alberto Donini describes his new “Relative Erosion”
dating method: “The REM is based on the ratio between two types of
erosion affecting the same type of rock in the same location: one with a
known date and the other with a date to be determined. The ratio is
then used to calculate the age of the stone block under examination.”
When the pyramids of Giza were built, they were covered in a gleaming
casing of smooth, polished, white limestone. Then, in 1303, a massive
earthquake struck the region, knocking some of these stones to the
ground. The fallen material was recycled to build palaces and mosques in
Cairo, and in the years that followed, even more of the limestone was
removed intentionally to use for decorative purposes. By 1400, much of
it was gone.
Alberto DominiA small section of the Great Pyramid where the smooth, white limestone cladding still remains.
Donini began his research by comparing the areas of the Great Pyramid
that were once covered by limestone with stones at the structure’s base
that have always been exposed to the elements. By comparing the amount
of erosion that’s taken place in the past seven centuries to the amount
of erosion on the blocks that were never covered by limestone, Donini
believed he could calculate when those original stones were placed.
Donini noted that erosion occurs by several means. Water is a major
source, from runoff dripping onto surfaces to trickles of liquid seeping
into small cracks, freezing, and expanding. Wind blowing rough sand
from Egypt’s desert also wore down the limestone over time, as did
temperature fluctuations, acid rain, and surface wear from humans
touching and walking on the surfaces.
There were several factors that Domini took into account while making
his calculations. First, he acknowledged that there’s been an increase
in foot traffic in the modern era, leading to more surface erosion in
recent years than in ancient times. There’s also likely been more acid
rain since the Industrial Revolution. These elements could lead to an
underestimation of the Great Pyramid’s age.
Alternatively, the climate was wetter in ancient times, so more rain
then could have led to faster erosion rates than those seen in the past
few centuries. This, in turn, could lead to an overestimation of the
monument’s age.
