https://www.britishmuseum.org/collection/object/P_1906-0509-1-27
In around about 1580 the artist John White produced this picture of how he imagined an historical Pictish woman would have looked.
Tattooing of the body has been practiced for thousands of years. The oldest known human to have tattoos preserved upon his mummified skin is a Bronze-Age man from around 5000 years ago. Found in a glacier of the Otztal Alps, near the border between Austria and Italy, ‘Otzi the Iceman’ had 57 tattoos. They were mainly simple dot tattoos and they seem to have marked acupuncture points on his body. Other tattooed mummies have been recovered from at least 49 archaeological sites all over the world. Charles Darwin wrote (In ‘The Descent of Man’ 1871) that there was no country in the world that did not practice tattooing or some other form of permanent body decoration.
How long people have been tattooing themselves in the British Isles is debatable. There are no ancient mummies or texts to study. One of the earliest mentions is from Julius Caesar who wrote in his book 'De Bello Gallico' of the Celts “All the Britons dye themselves with a dye made from the plant woad, which produces a blue colour, and makes their appearance in battle more terrible.” It is not clear if this was actual tattooing or body paint as has been depicted in films like 'Braveheart'. Woad is primarily used as a fabric dye, but it seems to have some anti-septic properties and could have been used as a wound dressing after battles and thus colored the resulting scars, making them dramatic souvenirs of bravery. Actual tattooing would probably have used soot, iron and copper to make pigments.
Woad
There are many mentions of the 'Picts' who lived in Scotland. Julius Caesar described them as "Pictorial People" (hence 'Picts) who "pricked diverse marks into their skin." The historian Herodian wrote in his Historium "they puncture their bodies with pictured forms of every sort of animals; on which account they wear no clothing, lest they should hide the figures on their body. They are a most warlike and sanguinary race, carrying only a small shield and a spear, and a sword girded to their naked bodies." In the third century Solinius wrote of tattooed Britons in his book Collectum Rerum Memorabilium "That region is partly held by barbarians, who from childhood have different pictures of animals skillfully implanted on their bodies"
So it seems from these accounts there is a long tradition of tattooing in the British Isles going back thousands of years.