05 June 2013 by Michael Marshall
IT'S the admin centre of the ancient world. The workers who built the pyramids of Giza and the accountants and managers who organised them achieved architectural immortality – but you wouldn't know it from where they lived. Built in a flood zone, their town was repeatedly destroyed by flash floods. Bizarrely, the Egyptians kept rebuilding in the same place despite the continual devastation.
During the reign of the pharaoh Menkaure, thought to be between 2532 and 2503 BC, Egypt was run from a city on low ground near the Giza plateau. Known as Heit el-Ghurab, this was a large administrative centre surrounded by houses, workshops and bread ovens. After decades of occupation, it was abandoned and buried under tens of metres of sand.
Karl Butzer of the University of Texas at Austin and colleagues have been excavating Heit el-Ghurab since 2001. They discovered layers of muds and sands, which they dated by identifying the relics in them, as well as radiocarbon dating.
The team found that the site was hit by three floods in 26 years during the reign of the previous pharaoh, Khafre. The first destroyed the town, while the others caused widespread damage. But under Menkaure the devastation multiplied.
Menkaure built the big admin complex, only to see it demolished. "A huge flood came barrelling through," says Butzer. It carried a torrent of rocks and mud, smashing buildings to pieces.
Above that, Butzer found "layer after layer of foundations and then rubble", attesting to frantic rebuilding following a further four or five flash floods. Menkaure ordered the construction of a 70-metre-long defensive barrier called the Wall of the Crow, yet flooding continued. Another flood struck soon after Menkaure's death. In total, Heit el-Ghurab flooded 10 times within about 45 years. Further flooding may have occurred later, but no sediments have survived to record them (Journal of Archaeological Science, doi.org/mpk).
It's not clear why the ancient Egyptians kept rebuilding the city in the same dangerous place. "It doesn't make any sense," says Butzer. People do build houses on floodplains, but not if they get swamped every four years.
It's doubly strange because ancient Egyptians paid close attention to the weather, says Stefan Kröpelin of the University of Cologne in Germany. "Generally they were much more sensitive – they knew the weather was changing and they reacted." Even the foundation of the Egyptian kingdoms may have been driven by climate, as the drying Sahara forced people towards the Nile, Kröpelin says.
Menkaure might be to blame, says Butzer. "He had a problem with his sense of importance. He was the divine offspring of the gods, and he thought if he prayed hard enough things would be OK. They weren't."
The floods may explain why there are only three pyramids at Giza. Menkaure built the last, and smallest, of them. Later pyramids were built elsewhere, despite the Giza plateau's prime position, which meant its pyramids are visible from great distances. "Menkaure was the last one," says Butzer. "Maybe there was a reason his son wanted to go someplace else."