The Giza Plateau has three main pyramids. The pyramid of Menkaure, the pyramid of Khafre and the great pyramid of Khufu. As per today's widely accepted assumptions, the pyramid of Menkaure was probably completed in the 26th century BC. The Pyramid of Khafre was built during the reign of Khafre, who ruled from 2558 to 2532 BC. The Great Pyramid of Khufu was built during 2580-2560 BC. These dates are acknowledged by Dr. Zahi Hawass as well, who is director of the archeology department of Egypt and holds the supreme command in ancient Egyptology. (His team's recent achievement is the discovery of the mythical tomb of Osiris, god of the dead in ancient Egypt. That was truly a wow news for me, and all other readers. [caption id="" align="aligncenter" width="277"] The only known statue of Khufu is only 7.5 cm high x 2.9 cm long x 2.6 cm deep. Discovered in 1903[/caption]

Another group of researchers claims something else. According to Robert Bauval, the Giza pyramids are a stellar representation of Orion's Belt (a well-known constellation of our Milky way galaxy). In his "Orion correlation theory", he states that the three pyramids of Giza are an exact mapping of three stars in the Orion constellation. The location & distance in between the pyramids represents three stars, whereas the Milky Way was associated with the River Nile. As per his theory, this mapping happened in the 10th millennium BC; hence, pyramids were built much, much before the Egyptian civilization. (watch the BBC documentary which is very convincing on this topic).

[caption id="" align="aligncenter" width="288"] The stars in Orion's Belt (in the middle) mapped with the three pyramids of Giza.[/caption]

So the dates  and actual builders of these pyramids are still a mystery (at least for me). The archeology department of the Egyptian government has official statements that the pyramids were built from 2700 BC to 2500 BC by the rulers of that time.