@Bohemond I seem to remember that Japan had/has a custom of adopting a daughters husband as a legit son of the family. He takes on his wife's family name instead the norm of the wife marrying out and taking up the family name of the husband. It was mostly a way to scout talent or get a male heir if the family only had daughters. So like Soulbourne said it's hardly a new custom to adopt, and it's not just limited to the recent-ish west and Rome. I'm sure other examples could be found if one made the effort to look.
0
@Bohemond I seem to remember that Japan had/has a custom of adopting a daughters husband as a legit son of the family. He takes on his wife's family name instead the norm of the wife marrying out and taking up the family name of the husband. It was mostly a way to scout talent or get a male heir if the family only had daughters. So like Soulbourne said it's hardly a new custom to adopt, and it's not just limited to the recent-ish west and Rome. I'm sure other examples could be found if one made the effort to look.