https://en.m.wikipedia.org/wiki/List_of_royal_marriages_to_commoners
Couldn't find one of nobility, but I choose to believe that is because of how many there were, even if uncommon, throughout history.
For the most part cases were from eastern europe. And for the most cases those marriages were morganatic (meaning children and wife cannot inherit anything related to titles/land).
Some cases state that ruler was deposed (1 year) and in either cases marriage to non noble women was frowned upon.
That marriage is basically glorified concubine.
The only case where a servant was married to a royal is Peter the 1st of Russian empire. (But that one is just nasty though, she was wife to some already, she was treated as mistress by other men (when Russian empire conquered baltics from Swedes) and that weird Peter the 1st took her as his wife, nobody could oppose his decisions since he already had an official successor + at that time Russian nobility wasn't so organized, Peter the 1st was actually the one who introduced "western" style nobility system. He had a wife already and a successor from the 1st marriage)
Also almost everywhere the only people who could allow to marry commoners were royals and by that male royals.(There is no higher authority to ban that) But even that could cause great political problems.
And even wiki only proves my point: SERVANT boy cannot marry a noble woman, while the opposite is more plausible it's rare and is frowned upon.
Also like i stated man to women(noble) usually was met with strong opposition and in many cases that said women became disowned (thus became a commoner). Male(noble) to female was usually met with assassinations of a woman.
In all cases in wiki only males (noble) married to commoners and most of them were from merchant families i.e. merchant families could sometimes be richer than royals.
Anything after 19th century is irrelevant due to revolutions and dismantlement of a class called "noble" and the rise of wealthy class.