An interesting way of thinking about this is not to ask why medieval (and subsequent) royalty and nobility might sleep separately, but why ANY couple might sleep in the same bed. read more
Certain rituals bring the two together (evening banquets, viewing theatrical performances in the court, and sex). But that did not necessarily include sleeping together. Rather, outside of these ritualistic practices, a king and queen would separate to their own suite of rooms, and spend time with others. 3. read more
Meanwhile, many medieval kings regularly went to war and travelled through lawless territory where it was not wise to bring their entire family. As a result, kings and queens not only had separate bedrooms, but also separate households of knights, servants, carters and hangers-on. read more