The Lopukhin family was a noble family of the Russian Empire, forming one of the branches of the Sorokoumova-Glebov family. One of its members, Eudoxia Lopukhina, married Peter the Great. When Pyotr Lopukhin's son died childless, the family's princely title passed to
Eudoxia was Russian.
We know the family was from the Russian Empire, but we don't know if Eudoxia married in, and if she did, whether she was of another nationality. I think the system didn't understand how nationality and marriage works!