This is not a comprehensive study of every sexual quirk, kink and ritual across all cultures throughout time, as that would entail writing an encyclopaedia. Rather, this is a drop in the ocean, a paddle in the shallow end of sex history, but I hope you will get pleasantly wet nonetheless. The act of sex has not changed since people first worked out what went where, but the ways in which society dictates how sex is culturally understood and performed have varied significantly through the ages. Humans are the only creatures that stigmatise particular sexual practices, and sex remains a deeply divisive issue around the world. Attitudes will change and grow – hopefully for the better – but sex will never be free of stigma or shame unless we acknowledge where it has come from.