We could begin with civilization, nearly 6,000 years ago at Sumer. New years in Sumer are supposed to have started with a sacred rite. They had sex in a temple, and made the land fertile. Purely apocryphal, probably. A little later, in Egypt, Amenophis III, father of Akhenaten, started a harem with Tiy, his one Great Wife.
Descriptions tend to be rough, but uniform.
Take, for instance, R.H. van Gulik's survey, Sexual Life in China . Lesser men kept fewer women. Van Gulik is explicit about how women were picked, cared for and copulated with. By Tang times, kings had meticulous books kept on the hour of every insemination, the date of every menstruation and the first signs of every conception. I could go on.