A statue carved from the ground
The Great Sphinx is not built from stacked blocks like the nearby pyramids. It was cut out of a mass of natural limestone bedrock on the Giza plateau. The figure is roughly 73 metres long and 20 metres high, though different sources round these numbers differently. Builders appear to have used a hollow in the plateau, left by quarrying, and shaped the outcrop that remained into a lion’s body and a human head. Blocks removed during the work were used in nearby structures. The Sphinx Temple in front of it is built from large limestone blocks that seem to have come from the area where the statue was cut, though this match is reasoned from geology and not documented by text.
Egyptian sculptors worked with copper tools, stone pounders and abrasives. Carving a figure of this size from soft stone needed careful planning, with the rough shapes cut first and then smoothed. Traces of red paint have been reported on the face, and it is likely the monument was once painted, as most Egyptian sculpture was. This is the sort of detail that shows up only with close study, and it supports the general view that the Sphinx was finished and decorated as a royal monument.
The geology matters
The Sphinx is carved from layers of limestone of different quality. The head is cut from a harder layer, while the body lies in softer, more crumbly beds. This explains much of the uneven condition: the body has lost more stone than the head over time. Throughout its history, the Sphinx has needed repairs and patching with blocks, some of which were added in antiquity and more in the modern period. Repairs of earlier eras can sometimes be dated by the style of masonry used.
Dating the Sphinx
Most Egyptologists date the Sphinx to the reign of Khafre in the Fourth Dynasty, about 2500 BCE. The case is circumstantial but strong. The Sphinx sits within Khafre’s complex, with the Sphinx Temple aligned to the valley temple and the causeway, and the quarry that produced it is linked to the surrounding construction. The pattern of the tombs and structures around it matches the Fourth Dynasty. No inscription from the time names the builder, so the date depends on context, as with many Old Kingdom works. A minority view has attributed it to Khufu or to his son Djedefre, but these are not widely accepted.
The erosion debate
In the 1990s, the geologist Robert Schoch argued that the pattern of weathering on the Sphinx enclosure looked like water erosion from heavy rainfall, which he concluded implied an earlier date than the Old Kingdom, thousands of years earlier. Egyptologists and many geologists have responded that the weathering can be explained by other causes. These include salts drawn up from the ground, wind-blown sand, humidity and varying layers of rock. They also point out that there is no archaeological evidence for a society capable of such a monument that early, and that the Sphinx fits so closely with the surrounding Fourth Dynasty features. The debate illustrates how geological interpretation and archaeological context can lead to different conclusions, and the general consensus remains with the Khafre dating.
Scientific dating techniques, including radiocarbon dating, work on organic materials, so they cannot date carved rock directly, and the date of the Sphinx depends on other lines of evidence.
Sand, burial and clearing
The Sphinx has often been buried up to its shoulders in drifting sand. According to the Dream Stele, Thutmose IV cleared it in the New Kingdom, around the 14th century BCE. Sand returned, and later partial clearances took place in Roman times. In 1817 an expedition led by Giovanni Battista Caviglia uncovered the chest, and further work followed in the nineteenth century. In the 1920s and 1930s, the engineer Émile Baraize led a larger clearing for the Egyptian Antiquities Service, exposing the whole body and the platform around it. Photographs from earlier eras are a reminder of how buried it was.
The nose and beard
The nose is missing, and the cause is not documented in detail. It was not shot off by Napoleon’s army, as a persistent story says, because earlier drawings already show the loss. Some medieval writers attribute damage to a religious zealot centuries earlier. The ceremonial beard was added later; pieces were recovered and are now in museum collections, in Cairo and the British Museum.
Restoration and conservation
Weathering continued in the twentieth century, and large pieces of stone fell from the body. Earlier repairs used cement-based mortars, which in some cases proved unsuitable and damaged the original stone. From the 1980s onward, conservators replaced such material with more compatible limestone and developed methods to handle groundwater and salts. The ongoing work involves monitoring, documentation and protection from pollution and rising groundwater, a problem facing many ancient sites. Careful archaeological methods, from detailed recording to environmental monitoring, are now standard in the conservation of the monument.
The Sphinx is thus both an ancient work and a heavily managed one. Much of what visitors see is original, but parts of its surface are repairs.