Infrared image of the male mummy known as Gebelein Man)
Photograph by The Trustees of the British MuseumUnder infrared light, the details of the tattoo on his 5,000-year-old skin become visible.
Photograph by The Trustees of the British MuseumUnder regular light, the details are less prominent. When first found in 1900, the tattoo was mistaken for a smudge.
Photograph by The Trustees of the British MuseumThe female Gebelein woman was also examined under infrared light.
Photograph by The Trustees of the British MuseumHer shoulder bone bears four "S"-shaped lines. The pattern has been found on other pieces of art from this time period.
Photograph by The Trustees of the British MuseumOn her abdomen, the Gebelein woman has a tattoo of a stave, or staff. One theory archaeologists have about their meaning is that the "S" shapes point to or emphasise the stave.
Photograph by The Trustees of the British Museum