According to the legend engraved on a pink granite slab between the Sphinx’s paws, the Egyptian prince Thutmose went hunting in the desert, grew tired and lay down in the shade of the Sphinx. In a dream, the statue, calling itself Horemakhet—or Horus-in-the-Horizon, the earliest known Egyptian name for the statue—addressed him. It complained about its ruined body and the encroaching sand. Horemakhet then offered Thutmose the throne in exchange for help.
Whether or not the prince actually had this dream is unknown. But when he became Pharaoh Thutmose IV, he helped introduce a Sphinx-worshiping cult to the New Kingdom (1550-1070 B.C.). Across Egypt, sphinxes appeared everywhere in sculptures, reliefs and paintings, often depicted as a potent symbol of royalty and the sacred power of the sun.
Based on Lehner’s analysis of the many layers of stone slabs placed like tilework over the Sphinx’s crumbling surface, he believes the oldest slabs may date back as far as 3,400 years to Thutmose’s time. In keeping with the legend of Horemakhet, Thutmose may well have led the first attempt to restore the Sphinx.
When Lehner is in the United States, typically about six months per year, he works out of an office in Boston, the headquarters of Ancient Egypt Research Associates, a nonprofit organization Lehner directs that excavates the Lost City and trains young Egyptologists. At a meeting with him at his office this past fall, he unrolled one of his countless maps of the Sphinx on a table. Pointing to a section where an old tunnel had cut into the statue, he said the elements had taken a toll on the Sphinx in the first few centuries after it was built. The porous rock soaks up moisture, degrading the limestone. For Lehner, this posed yet another riddle—what was the source of so much moisture in Giza’s seemingly bone-dry desert?
The Sahara has not always been a wilderness of sand dunes. German climatologists Rudolph Kuper and Stefan Kröpelin, analyzing the radiocarbon dates of archaeological sites, recently concluded that the region’s prevailing climate pattern changed around 8,500 B.C., with the monsoon rains that covered the tropics moving north. The desert sands sprouted rolling grasslands punctuated by verdant valleys, prompting people to begin settling the region in 7,000 B.C. Kuper and Kröpelin say this green Sahara came to an end between 3,500 B.C. and 1,500 B.C., when the monsoon belt returned to the tropics and the desert reemerged. That date range is 500 years later than prevailing theories had suggested.
Further studies led by Kröpelin revealed that the return to a desert climate was a gradual process spanning centuries. This transitional period was characterized by cycles of ever-decreasing rains and extended dry spells. Support for this theory can be found in recent research conducted by Judith Bunbury, a geologist at the University of Cambridge. After studying sediment samples in the Nile Valley, she concluded that climate change in the Giza region began early in the Old Kingdom, with desert sands arriving in force late in the era.
The work helps explain some of Lehner’s findings. His investigations at the Lost City revealed that the site had eroded dramatically—with some structures reduced to ankle level over a period of three to four centuries after their construction. “So I had this realization,” he says, “Oh my God, this buzz saw that cut our site down is probably what also eroded the Sphinx.” In his view of the patterns of erosion on the Sphinx, intermittent wet periods dissolved salt deposits in the limestone, which recrystallized on the surface, causing softer stone to crumble while harder layers formed large flakes that would be blown away by desert winds. The Sphinx, Lehner says, was subjected to constant “scouring” during this transitional era of climate change.
“It’s a theory in progress,” says Lehner. “If I’m right, this episode could represent a kind of ‘tipping point’ between different climate states—from the wetter conditions of Khufu and Khafre’s era to a much drier environment in the last centuries of the Old Kingdom.”