Irregular Webcomic! #1425

Djoser ruled as Pharaoh of Egypt from 2668 BC to 2649 BC, the second Pharaoh of the IIIrd Dynasty of the Old Kingdom. He instructed his royal architect Imhotep to build him a monument. Imhotep, being a brilliant architect and philosopher, rather than a bloodthirsty mummy as depicted in multiple horror films, designed an amazing monument the likes of which had never been seen before.

He took the traditional mastaba design, and stacked six of them on top of one another, in decreasing size, to produce the famous Step Pyramid of Djoser, at the necropolis of Saqqara. This astonishing new direction in architecture was the first step (ha!) towards the giant straight-sided pyramids we know and love.

2016-08-03 Rerun commentary: There are also another couple of interesting intermediate forms between the Step Pyramid of Djoser and the familiar straight-sided pyramids of Khufu and his ilk that were to come a century or so later.

Around 2620 BC, Huni, the last pharaoh of the IIIrd Dynasty (three successors removed from Djoser), is thought to have commissioned a step pyramid of his own at Meidum, about 100 km south of Cairo. Pharaohs not being known for settling for second best, his pyramid consisted of eight layers, two more than Djoser's, and was both steeper and higher.

Archaeologists are still sorting out some of the details, but most generally take the available evidence to indicate that construction of the Meidum pyramid was taken over by Huni's successor, Sneferu, the first pharaoh of the IVth Dynasty of the Old Kingdom. Sneferu decided he would make a new type of monument by adding an outer shell to the original step pyramid design, encasing it in limestone, with a smooth, straight, sloping outer surface. This would turn the construction into a regular pyramid shape.

Unfortunately, Imhotep's original step pyramid design for Meidum wasn't engineered to support this. The area immediately around the step pyramid was unstable sand, and horizontal surfaces of the steps were slightly sloped, making them less than ideal places to rest tons more rock. The inevitable result was that the outer casing collapsed, falling off and leaving the original stone step pyramid inside exposed. And this is what the Meidum pyramid looks like today - a steep step pyramid, surrounded by a bunch of rubble.

Besides adding on to Huni's legacy, Sneferu also wanted a pyramid of his own. And this was going to be the first purposely built true (pyramidal shaped) pyramid, rather than a conversion of a step pyramid. He decided to have it built at Dahshur, about 40 km south of Cairo. It was to be an impressive pointed structure, rising from the desert with the straight walls sloped at an angle of 54° to the horizontal.

But about a third of the way up, Sneferu's engineers realised that if they continued building at that angle, the structure would be unstable. They may have been pushed to this conclusion by the collapse of the outer shell of the Meidum pyramid (it's unclear exactly when that happened). So they decided in the interests of safety and posterity to reduce the angle to a shallower 43°, and continue like that to the top. Whether this was necessary or not, the resulting pyramid has survived 4600 years and can be seen today, complete with its distinctive bent sides that give it its modern day appellation of the Bent Pyramid.

Having learnt his lesson, Sneferu went on to commission a third pyramid. A true mathematical pyramid - the first one built by the Ancient Egyptians. It was constructed right next to the Bent Pyramid, and is known today as the Red Pyramid.

And that, from mastabas, via Djoser's stacked up Step Pyramid, through Meidum, the Bent Pyramid, to the Red Pyramid, is a brief history of the development of everyone's favourite building shape! Although I have a better name for the rather prosaically named "Bent Pyramid": Sneferu's Snafu.