The 2ft 1in (65cm) group of Mehernefer and his son dates to c.2400- 2300BC and will be offered with an estimate in excess of £4m at the July 7 Exceptional auction.
Christie’s antiquities specialist Claudio Corsi said the statue was presented to George III as a gift from Sir James Porter while he was ambassador in Constantinople from 1746-61. The king later gave the statue to Thomas Worsley (1797-1885) of Hovingham Hall, where it remained and is documented in the archives of the North Yorkshire stately home since 1778.
It is believed to be one of the first Old Kingdom objects to arrive in England.
An inscription on the sculpture of the boy identifies him as the God’s Servant- Prophet of Wadjet and King’s Agent in Nubia, Meher-nefer. The original find spot is not known, but it is likely it was taken from an enclosed serdab chamber within a mastaba tomb at either Giza or Saqqara.
George III also gave Worsley a Giambologna statue of Samson and a Philistine and the two sculptures were on display together.