It is all set out in the marriage contract.
In real life usually the name of the highest-ranked partner was commonly chosen. In the case of (nearly) equal ranks, both names can be used.
But it's basically up to you.
Write it out in your contract, You should have options to do that.
No man will make a great leader who wants to do it all himself or get all the credit for doing it. -Andrew Carnegie
Become the kind of leader that people would follow voluntarily; even if you had no title or position. -Brian Tracy
Posted By Felsing at 3:40 PM - Wed Jul 11 2018
Will marrying someone of greater rank increase your rank?
Not unless specified in the marriage contract. You can grant them certain powers but the actual title remains with the original holder. Though I think NPCs would refer to you by the title of the spouse. As for increasing fame rank...
Spouses of characters with high levels of notoriety and fame will not not incur the same amount of spirit loss as their partner upon death, unless they themselves are of the same level of fame. However, having a spouse with a high level of fame also increases your own level of fame (just not to the same degree.[4]