A reader looking into the histories of tattoos must realize that they were not known as tattoos since that is a Polynesian term that originated in the eighteenth century in a journal by Captain James Cook (it is one of two words in the standard English lexicon that comes from Polynesian sources; the other is taboo). Tattoos were indelible pigmentation inserted under the skin and were before 1760 known as markings, incisions, pricking or even painting. We see samples on the “Iceman” Ötzi, in China, in Egypt, Japan and, of course, Polynesia.
Tattoos were used by the Celts, by the Anglo-Saxons and by the Norse. Ahmed ibn Fadlan’s description of the marks on Rus Vikings is well known, and tattoo enthusiasts have come up with an exaggerated history of their use that takes the slightest indication and expand it immeasurably. For the most part, these tattoos were symbols of heathen faith, and there was a steady attempt by the Church to get rid of them, though that never seems to have been complete.
What were the tattoos for? Apparently as magical symbols, as medicinal marks, for identification and for the same reason that many tattoos are applied nowadays, because they’re cool art. Were they part of the sex life or considered sexually attractive? Probably so, though you can never tell since they are not generally talked about.
What did the tattoos look like? Well, we have those on the body of Ötzi, which predates the Viking Age quite a bit; and we have the ambiguous description by ibn Fadlan, that the Viking males were covered from “fingernails to neck” with dark blue or dark green “tree patterns” and other “figures.” Whether this was actual flora knotwork or runes remains uncertain, so we do not know what tattoos were worn by the Norse!
It is interesting to note that some folk—particularly prudes and modern tattoo-removal doctors—insist that the Norse had no tattoos. The ultimate truth, perhaps, will not be revealed until we find a flash frozen Norse Ötzi!