Great Pyramid of Giza

The Great Pyramid is the largest of the three pyramids on the Giza plateau, near modern Cairo. It was built as the tomb of Khufu, a king of Egypt’s Fourth Dynasty during the period historians call the Old Kingdom. The Greeks, who wrote about it about two thousand years later, called the king Cheops. The Egyptians called the pyramid Akhet Khufu, meaning “Horizon of Khufu”, the place where the king would rise into the sky like the sun at dawn.

Its size is still astonishing. The pyramid originally stood about 146.6 m tall; it has lost its top and outer casing and is now about 138.5 m high. Each side of its square base measures about 230 m, and the base covers more than five hectares. Estimates suggest it contains around 2.3 million blocks of stone. For thousands of years it was the tallest structure made by human hands anywhere on earth.

The Greeks later counted it among the Seven Wonders of the World, a list of famous monuments admired by travellers. All the others, such as the Hanging Gardens of Babylon and the Colossus of Rhodes, have vanished or survive only in ruins. The Great Pyramid, the oldest of them, is the only one still standing.

Outside, what we see today is the stepped core of large, roughly cut limestone blocks. Originally the whole surface was covered by finely polished white limestone quarried at Tura, across the Nile. The casing blocks were fitted so tightly that the joints between them were extremely thin. A few casing stones still remain at the base. The pyramid’s sides face almost exactly north, south, east and west; the error is only a few minutes of arc, a fraction of a degree.

Inside, the entrance is on the north face. A descending passage leads down into the bedrock to an unfinished underground chamber. An ascending passage leads upwards to a horizontal corridor and a room known as the Queen’s Chamber, a name given by later explorers; no queen was buried there. Continuing upward, the passage opens into the Grand Gallery, a tall, narrow hall with a corbelled ceiling about 8.6 m high and more than 46 m long.

At the top of the Grand Gallery lies the King’s Chamber, lined entirely with red granite brought from Aswan, about 800 km to the south. It holds a lidless granite sarcophagus, which was empty when explorers reached it. Above the chamber are five low compartments separated by huge granite beams. These “relieving chambers” helped spread the weight of the masonry above. Narrow shafts lead from the King’s and Queen’s Chambers towards the outside; their purpose, whether for air or for the king’s spirit to reach the stars, is debated.

All around, the pyramid was the centre of a larger complex. On its east side stood a mortuary temple, where offerings were made for the dead king; a causeway led down to a valley temple near the edge of the cultivated land. There were three small pyramids for queens, a small satellite pyramid, several pits for full-sized boats, and rows of stone tombs called mastabas where members of the royal family and officials were buried to stay close to their king.

Khufu was the son of King Sneferu, the most ambitious pyramid builder before him. Sneferu built at least three large pyramids at Meidum and Dahshur, including the Bent Pyramid, where the builders changed the angle part way up, and the Red Pyramid, the first true smooth-sided pyramid. Khufu’s builders took that experience and pushed it to its limit.

About a century before, King Djoser’s architect Imhotep had built the first large stone pyramid at Saqqara, the Step Pyramid, a stack of six stone platforms. In just a few generations, Egyptian builders moved from that step shape to the enormous, precise geometry of the Great Pyramid. This rapid progress shows how powerful and well organised the Egyptian state had become.

Surprisingly little is known about Khufu as a person. The only certainly identified complete statue of him is a tiny ivory figure about 7.5 cm tall, found by Flinders Petrie at Abydos in 1903. Much later Egyptian tales and the Greek historian Herodotus portrayed him as a harsh ruler, but those stories were written long after his death and cannot be taken as reliable history. Egyptians continued to honour him with a cult for many centuries.

Most of the core blocks were cut from a quarry on the Giza plateau itself, just south of the pyramid. Workers used copper chisels and saws, wooden wedges, stone pounders and sand as an abrasive; hard granite was shaped mainly by pounding with dolerite stones and grinding. The fine casing limestone came by boat from Tura, and the granite from Aswan was floated down the Nile.

How the blocks were raised is one of the most discussed questions in archaeology. Many Egyptologists think that ramps of mud brick, rubble and limestone chips were used, but they disagree about the form: a long straight ramp, a ramp spiralling around the pyramid, zigzag ramps on one face, or combinations. The architect Jean-Pierre Houdin has proposed an internal ramp, an idea that has not been widely accepted. Levers and sledges were certainly used. A painting from a Middle Kingdom tomb shows a colossal statue pulled on a sledge while a worker pours liquid in front of it, and experiments suggest that wetting sand greatly reduces friction.

Archaeology has recently added new evidence. In 2018 a team working at the Hatnub alabaster quarry reported a steep ramp from about the time of Khufu with post holes and stairs on each side, suggesting a system for hauling blocks up steep slopes. Studies of ancient sediments have shown that a branch of the Nile and connected basins once came much closer to Giza than today, allowing boats to deliver stone close to the building site.

Planning and accuracy were remarkable. The base is almost perfectly level and square, and the orientation to true north is precise to within a few arc-minutes. How the Egyptians achieved this is debated: proposals include sighting on stars circling the celestial pole, or using the shadow of a vertical rod to track the sun. Tradition names Hemiunu, a royal relative and vizier whose large tomb lies west of the pyramid, as overseer of the king’s works.

The popular picture of slaves driven by whips is not supported by the evidence. Since the late 1980s, archaeologists led by Mark Lehner have excavated a settlement south of the Giza plateau, known as Heit el-Ghurab or the “Lost City of the Pyramid Builders”. It contained bakeries, breweries, storerooms, workshops and barracks-like galleries, along with huge quantities of animal bones showing that workers received beef, sheep, goat and fish.

Nearby, Zahi Hawass excavated cemeteries of workers and overseers beginning in 1990. People were buried in small tombs with offerings, close to the king’s monument, which suggests their work was seen as honourable. Skeletons show heavy physical labour, but also healed fractures and even signs of surgery, indicating that injured workers received care.

Most scholars think the workforce combined a permanent core of skilled craftsmen and managers with larger groups of labourers who served in rotation, probably as a kind of obligatory service owed to the state. They were organised into crews and gangs with names; graffiti left inside the relieving chambers include gang names formed with the name of Khufu. Herodotus wrote that 100,000 men worked in three-month shifts for twenty years, but modern estimates of the number of workers at any one time are much lower, generally in the tens of thousands at most, and vary widely.

In 2013 a French-Egyptian mission led by Pierre Tallet discovered papyri at Wadi al-Jarf, an ancient harbour on the Red Sea. Among them is the Diary of Merer, a logbook kept by an inspector who led a team of about 40 men. It records how the team carried limestone blocks from the Tura quarries across the Nile to Giza, stopping at a harbour called She-Khufu, in about the 27th year of Khufu’s reign. It also names Ankhhaf, the king’s half-brother, as a senior official. These are among the oldest inscribed papyri known, and they give us a direct voice from the pyramid project.

For the Egyptians the king was a link between the gods and people. When he died, he was believed to join the gods, rising to the sky to travel with the sun god Ra and to take his place among the “imperishable” stars around the north celestial pole. The pyramid was the machine for that transformation: a place to protect his body and to support his eternal life through offerings and rituals.

The pyramid shape probably had solar meanings. It recalls the benben, the sacred stone associated with the mound that rose from the waters at creation, and it may also evoke the rays of the sun spreading down to earth. The name Akhet Khufu, “Horizon of Khufu”, connects the king with the place where the sun rises and sets. The spells called the Pyramid Texts, which describe the king’s ascent, were carved inside pyramids only from the end of the Fifth Dynasty, about two centuries later, so using them to explain Khufu’s pyramid requires caution.

The pyramid was also a statement of royal power. Building it required organising food, boats, tools, labour and knowledge across the whole country. Some historians argue that pyramid projects themselves helped create the Egyptian state’s administration, by forcing it to plan, count, record and supply resources on a vast scale.

The pyramid was probably robbed in ancient times; nothing of Khufu’s burial has been found inside. Greek and Roman writers such as Herodotus in the fifth century BCE described it and collected stories told by Egyptian guides. Medieval Arabic writers also described it, and tradition credits the Abbasid caliph al-Ma’mun, around 820 CE, with forcing the tunnel through which most visitors enter today, though the story is uncertain.

Much of the white casing was loosened by a severe earthquake in 1303 and later removed as building stone for Cairo, including for the Mosque-Madrasa of Sultan Hasan in the fourteenth century. That is why the pyramid looks rough and stepped today.

Scientific study began with the scholars of Napoleon’s expedition to Egypt (1798–1801). In 1837 Colonel Howard Vyse and John Perring used gunpowder to reach the upper relieving chambers, where they found painted marks and graffiti naming Khufu’s work gangs. Flinders Petrie’s careful survey of 1880–82 measured the pyramid with new precision. In 1954 the Egyptian archaeologist Kamal el-Mallakh discovered a pit on the south side containing a dismantled cedar boat more than 40 m long, now known as the Khufu ship. It was reassembled and later moved to the Grand Egyptian Museum.

The pyramid has also attracted many fringe theories, from nineteenth-century “pyramidology” to modern claims about lost civilisations or aliens. Archaeologists reject these: the quarries, tools, workers’ town, tombs, graffiti and papyri together show clearly that the pyramid was built by Egyptians in Khufu’s reign.

In 1979 the Giza pyramids were inscribed on the UNESCO World Heritage List as part of the site “Memphis and its Necropolis – the Pyramid Fields from Giza to Dahshur”. The plateau is managed by Egypt’s antiquities authorities and receives millions of visitors.

The site faces modern pressures: the expanding city of Cairo, traffic and pollution, groundwater changes, and the wear caused by large numbers of visitors. Climbing the pyramid is prohibited. The opening of the Grand Egyptian Museum near the plateau, which now houses the Khufu ship, is part of a broader effort to present Giza’s heritage to the world while protecting it.

Dating. Khufu’s reign is placed in the early-to-mid twenty-sixth century BCE, but different Egyptian chronologies vary by several decades. Radiocarbon dates obtained from organic material in the pyramid’s mortar have tended to come out somewhat older than the historical dates; one explanation is that builders burned old wood or reused old material, which would make samples appear older. The Diary of Merer confirms that work related to the pyramid was still under way late in Khufu’s reign.

Construction methods. No single ramp theory explains all the evidence. Straight ramps would require enormous volumes of material; spiral ramps would cover the corners needed for measurement; internal ramps lack direct confirmation. Many researchers now think a combination of techniques was used at different heights. The long-standing question of how the heavy granite beams of the King’s Chamber were lifted remains unresolved.

The interior. Were changes of plan made during construction? The unfinished underground chamber and the Queen’s Chamber have been interpreted either as abandoned burial chambers from earlier stages of a changing design, or as parts of a single original plan with different ritual functions. The Queen’s Chamber shafts, explored by Rudolf Gantenbrink’s robot in 1993, end at small stone “doors” with copper fittings whose purpose is unknown.

Hidden spaces. The ScanPyramids project, using muon imaging, announced in 2017 the discovery of a large void at least 30 m long above the Grand Gallery, and in 2023 confirmed a corridor about 9 m long behind the chevron stones above the north entrance. Whether the large void is a construction feature, such as a space to relieve weight or a construction gallery, or something else, is not known.

Written evidence from Khufu’s own time is rare but decisive: the painted gang names in the relieving chambers, the Merer papyri, and inscriptions in the tombs of officials and family members in the surrounding cemeteries. Later texts, such as Middle Kingdom tales and Herodotus, tell us how Egyptians and Greeks remembered Khufu, not what he was like.

Settlement archaeology has transformed the field. Excavations of the workers’ town and cemeteries, analysis of animal bones, bread moulds and pottery, and study of skeletons have shown how the project fed, housed and cared for its workers. Survey and mapping of the plateau, quarries and harbours reveal the logistics of stone supply.

Scientific methods now play a major role: precise laser surveys, radiocarbon dating, geology to trace the sources of stone, sediment coring to reconstruct ancient Nile channels, and non-invasive imaging such as muon tomography. Experimental archaeology tests how blocks could be cut and moved. Together these approaches show that the pyramid is best understood not only as a monument but as the product of a whole society.