In 1936, British Egyptologist Walter Bryan Emery was excavating Saqqara tomb S3111, a First Dynasty mastabaMastabaAn early Egyptian flat-roofed tomb with sloping sides, the architectural ancestor of the pyramid.→ attributed to a certain Sabu, when he found an object for which he had no precedent in all of Egyptian archaeology. Carved from a single block of grey schist, the object presents a trilobate form: three rounded lobes radiate from a hollow central hub, vaguely suggesting a three-bladed wheel or propeller. It measures 61 centimeters in diameter and only 10.6 cm in thickness, with edges so thin they appear almost translucent. Since its discovery, the "Sabu Disk" has remained one of ancient Egypt's great enigmas.

The Sabu Disk, trilobate schist, First Dynasty Egypt, Saqqara
The Sabu Disk (First Dynasty, c. 3100-3000 BCE), carved from a single block of grey schist. Its 61 cm diameter and unique trilobate form have no parallel anywhere in predynasticPredynasticThe period of Egypt before unification (c. 3100 BCE) and the First Dynasty, marked by the Naqada cultures and the gradual emergence of the state.→ and early dynastic Egypt. Credit: Wikimedia Commons

The object is now housed in the Egyptian Museum in Cairo (Room 43). Its dating is not disputed: the archaeological context of tomb S3111 places it unambiguously in the Egyptian First Dynasty, around 3100-3000 BCE, at the very dawn of pharaonic civilization. It is precisely this extraordinary antiquity that makes the object so difficult to interpret: Egyptologists have no contemporary texts that could explain its function.

The main interpretations

The interpretation most widely accepted by professional Egyptologists is that the Sabu Disk is a vessel or bowl: a container intended to hold oil, fat, or palm wine, with the three lobes serving as handles for gripping and pouring the contents. Formal parallels have been identified with spouted stone vases found in contemporary Mesopotamia, which could indicate cultural contacts or inspirations between the two nascent civilizations.

Sabu Disk face-on view, Egyptian Museum Cairo
Face-on view of the Sabu Disk. The extreme thinness of the edges (less than one centimeter in places) and the geometric regularity of the lobes attest to remarkable technical mastery for the period. Credit: Wikimedia Commons

Some researchers have proposed seeing it as a cosmetic palette, analogous to the schist palettes (often zoomorphic) that constitute a well-documented class of objects from the predynastic period and First Dynasty. In this case, the trilobate form would have a symbolic value linked to certain cosmogonic representations of the era.

A third interpretation, proposed by engineers and historians of technology, sees it as a representation of hydraulic equipment: a rotating bowl or platter on a hub, used in pottery or copper-working techniques. Practical experiments have shown that such an object, even in schist, could function as a lightweight rotating plate for ceramic finishing work.

Non-conventional theories

As often occurs with Egyptian objects of unusual form, the Sabu Disk has attracted the attention of non-conventional theorists who see in it evidence of a lost advanced technology. Some have proposed seeing it as a wheel, a propeller, or even an electrical machinery component. These interpretations, spread notably by websites and pseudo-scientific documentaries, do not withstand rigorous examination: schist is a fragile, non-conductive material that could not function as a load-bearing wheel, and no archaeological context supports the existence of rotating machinery in predynastic Egypt.

Technical drawing of the Sabu Disk by Walter Emery
Technical drawing of the Sabu Disk made by Walter Bryan Emery at its discovery in 1936. This record documents the exact proportions and trilobate structure of the object. Credit: Wikimedia Commons (public domain)

Egyptologist Kate Spence has noted that Sabu's mastaba contained relatively standard funerary goods for a high-ranking official of the First Dynasty: alabaster vases, knapped flints, ivory figurines. The disk may have been included in the funerary assemblage not because of its functional importance, but for symbolic reasons linked to the deceased's status or to specific beliefs concerning the afterlife in the first dynastic period.

The carving technique, a mystery in itself

Regardless of its function, the Sabu Disk raises the fascinating question of stone-carving techniques at the beginning of the Egyptian dynastic period. Obtaining this perfectly symmetrical trilobate form in a material as hard and brittle as schist, with the minimal edge thickness, implies considerable technical skill.

Mastaba S3503 at Saqqara, First Dynasty Egypt
Plan of mastaba S3503 at Saqqara, one of the First Dynasty large tombs excavated by Walter Emery. The Sabu Disk comes from mastaba S3111, in the same funerary complex. Credit: Wikimedia Commons

Experimental analyses using copper tools (the metal available at the time), abrasive sand, and percussion techniques have shown that the general form could be obtained by a patient and experienced craftsman in several dozen hours of work. The question of final calibration of the edge thickness remains problematic, however, and could indicate the use of a lathe or rotary jig not yet identified in the archaeological record.

The Sabu Disk remains a unique object, without confirmed parallel in the entire corpus of Egyptian art and material culture. This singularity makes it one of the most fascinating and least understood objects of Nile civilization, proof that even after 150 years of scientific Egyptology, the men and women of the first dynastic period still have secrets to reveal.