Some research suggests alternate estimates to the accepted workforce size.
For instance, mathematician Kurt Mendelssohn calculated that the workforce may have been 50,000 men at most, while Ludwig Borchardt and Louis Croon placed the number at 36,000.
Beginning with Djoser who ruled from 2687-2667 BCE, three other massive pyramids were built - the Step pyramid of Saqqara (believed to be the first Egyptian pyramid), the Bent Pyramid, and the Red Pyramid.
Also during this period (between 26 BCE) the Wadi Al-Garawi dam which used an estimated 100,000 cubic meters of rock and rubble was built.
It is generally believed the Great Pyramid was built as the tomb of Fourth dynasty Egyptian pharaoh Khufu (Cheops), after whom it is sometimes called Khufu's Pyramid or the Pyramid of Khufu.
Khufu's vizier, Hemon, is credited as the architect of the Great Pyramid.
Polish architect Wieslaw Kozinski believed that it took as many as 25 men to transport a 1.5-ton stone block.
Based on this, he estimated the workforce to be 300,000 men on the construction site, with an enormous additional 60,000 off-site.
There was a town for the workers of Giza, including a cemetery, bakeries, a beer factory and a copper smelting complex.
More buildings and complexes are being discovered by The Giza Mapping Project.
They derived these estimates from construction projects that did not use modern machinery.
This study fails to take into account however, especially when compared to modern third world construction projects, the logistics and craftsmanship time inherent in constructing a building of nearly unparalleled magnitude with such precision, or among other things, the use of up to 60-80 ton stones being quarried and transported a distance of over 500 miles.
Herodotus, the Greek historian in the 5th century BCE, estimated that construction may have required 20,000 workers for 20 years.