Historical records claim incest was rampant among rulers of ancient Egypt who believed they descended from the gods.
But this has always been difficult to prove because scientists were unable to get access to the mummies’ tissues for DNA analysis.
Now, a new study of 259 mummies has provided direct evidence of incest by measuring Pharaohs’ height variations and comparing it to the variation of the general Egyptian population at the time.
The study found Pharaohs varied less in height than common Egyptians suggesting incest was rife among royals.
‘It is actually one of the largest collections of body height of ancient Egyptians and spans all major periods of their history,’ Professor Frank Rühli from the University of Zurich told Discovery News.
The average height of the male population varied between 5.2ft (161 cm) in the New Kingdom during about 1550–1070 BC and 5.56ft (169.6 cm) during 2925–2575 BC.
This provides an average of 5.43ft (165.7cm) for all time periods.
Females ranged between 5.1ft (155.6 cm) from 712-332 BC to 5.23ft (159.5 cm) in the Early Dynastic period – providing an average height of 5.17ft (157.8 cm).
At 5.4ft (165 cm), tall King Amenhotep I was found to be one of the most obvious products of incest. Scientists believe he may have been born from three generations of sibling marriages.
Pharaohs such as Thutmosis III scored lower on the incestuous scale as their grandparents were siblings, but not his parents.
‘The study shows some evidence for consanguineous (incestuous) marriages in a reliable, non-invasive way,’ Barry Bogin, professor of biological anthropology at Loughborough University told Discovery News.
Previous DNA testing of King Tutankhamun revealed the Pharaoh was born from a marriage between siblings.
King Tutankhamun was known to be the son of the ‘heretic’ Pharaoh Akhenaten, who tried to reform the Egyptian religion during his rule.
But the identity of his mother had been shrouded in mystery until several years ago.
The fact that his mother and father were brother and sister may seem bizarre today but incest was rife among the boy king’s family because pharaohs were believed to be descended from the gods.
Therefore it was an acceptable way of retaining the sacred bloodline.
King Tut’s own wife Ankhesenpaaten, was his half-sister as they shared the same father. They were married when he was just ten.
But the research found generations of inbreeding took their toll on King Tut – the last of his great dynasty.
The bone disease he suffered runs in families and is more likely to be passed down if two first-degree relatives marry and have children.