@destinyfvcker in most comics, when the era of the time is set as "this" era (I quite don't know) Nobles have a set date on when the male goes to the females <intrest fancy word for room> to make an heir to the house in this case the ducal house
as I didn't do much research I don't know if real people did this, but I guess they did ¯\_(ツ)_/¯