He Married Him (to a Girl in His Care) in the Belief That He Was of Noble Lineage Then it Became Evident That He Was Not

Question :

A man proposed marriage to the daughter of another man claiming that he was from a noble lineage, so he married him (to her). Then it became evident that he was not from a noble lineage. What is the ruling?

Answer:

If the conditions in the aforementioned marriage contract were fulfilled, then the marriage is correct. But if the guardian of the woman made it a condition that the suitor be high-born, then it became clear that the case was otherwise, he has the choice, if he wishes, to leave his charge with him or, if he wishes, to demand a divorce.

If he has already had sexual intercourse with her, then the whole. dowry is for her, since he made her permissible through sexual relations with her. If he refused to divorce her, they must take the case to the Islamic Court Judge, that he may examine their case in the light of the Islamic Law, according to the words of the Prophet:
"Verily, the condition with the most right to be fulfilled is that by which sexual intercourse is deemed lawful (i.e. marriage)."

If he did not impose this as a condition, but simply believed his words and he did not consider it to be a condition of agreement to the marriage, then he has no choice as far as I am aware, in the Islamic Law. Because no conditions were made between them. The Arabs are suitable for each other, whether they are of a noble lineage or not. And a group of the scholars say that the Muslims are all suitable for each other, if they are straight in their religion, whether the husband is Arab and she is non-Arab, or a freed slave and likewise, vice versa. And this is a very strong opinion, based upon the aforementioned legal evidences.

Source:
Ibn Baz
Fatawa Islamiyah, Vol. 5 Pages 279-280