section_path: Age/History of dating Khufu and the Great Pyramid
section_name: History of dating Khufu and the Great Pyramid
paragraph_text: History of dating Khufu and the Great Pyramid
  
  Circa 450 BC Herodotus attributed the Great Pyramid to Cheops (Hellenization of Khufu), yet erroneously placed his reign following the Ramesside period. Manetho, around 200 years later, composed an extensive list of Egyptian kings, which he divided into dynasties, assigning Khufu to the 4th. However, after phonetic changes in the Egyptian language and consequently the Greek translation, "Cheops" had transformed into "Souphis" (and similar versions).
  
  Greaves, in 1646, reported the great difficulty of ascertaining a date for the pyramid's construction based on the lacking and conflicting historic sources. Because of the aforementioned differences in spelling, he did not recognize Khufu on Manetho's king list (as transcribed by Africanus and Eusebius), hence he relied on Herodotus' incorrect account. Summating the duration of lines of succession, Greaves concluded the year 1266 BC to be the beginning of Khufu's reign.
  
  Two centuries later, some of the gaps and uncertainties in Manetho's chronology had been cleared by discoveries such as the King Lists of Turin, Abydos, and Karnak. The names of Khufu found within the Great Pyramid's relieving chambers in 1837 helped to make clear that Cheops and Souphis are, in fact, one and the same. Thus the Great Pyramid was recognized to have been built in the 4th dynasty. The dating among Egyptologists still varied by multiple centuries (around 4000–2000 BC), depending on methodology, preconceived religious notions (such as the biblical deluge) and which source they thought was more credible.
  
  Estimates significantly narrowed in the 20th century, most being within 250 years of each other, around the middle of the third millennium BC. The newly developed radiocarbon dating method confirmed that the historic chronology was approximately correct. It is, however, still not a fully appreciated method due to larger margins of error, calibration uncertainties and the problem of inbuilt age (time between growth and final usage) in plant material, including wood. Furthermore, astronomical alignments have been suggested to coincide with the time of construction.
  
  Egyptian chronology continues to be refined and data from multiple disciplines have started to be factored in, such as luminescence dating, radiocarbon dating, and dendrochronology. For instance, Ramsey et al. included over 200 radiocarbon samples in their model.