Ottoman

The following is a fascinating documentary. It also allows some insight into how
a sultan with many wives (slaves  form East European captives) would have one male child
with each; it would not do for a leader to share a mother with a brother and potential rival;
a policy that makes no sense for demographic replacement, but is powerful in a context of war and conquest.

Incidentally, the Janissary elite troops mentioned herein were made of Europeans.