Sahih al-Bukhari Book 68, Hadith 35
The pagans were of two kinds as regards their relationship to the
Prophet and the Believers. Some of them were those with whom the
Prophet was at war and used to fight against, and they used to fight
him; the others were those with whom the Prophet (ﷺ) made a treaty, and
neither did the Prophet (ﷺ) fight them, nor did they fight him. If a lady
from the first group of pagans emigrated towards the Muslims, her hand
would not be asked in marriage unless she got the menses and then
became clean. When she became clean, it would be lawful for her to get
married, and if her husband emigrated too before she got married, then
she would be returned to him. If any slave or female slave emigrated
from them to the Muslims, then they would be considered free persons
(not slaves) and they would have the same rights as given to other
emigrants. The narrator then mentioned about the pagans involved with
the Muslims in a treaty, the same as occurs in Mujahid's narration. If
a male slave or a female slave emigrated from such pagans as had made
a treaty with the Muslims, they would not be returned, but their
prices would be paid (to the pagans).
Whenever Ibn `Umar was asked about marrying a Christian lady or a Jewess, he would say: "Allah has made it unlawful for the believers to marry ladies who ascribe partners in worship to Allah, and I do not know of a greater thing, as regards to ascribing partners in worship, etc. to Allah, than that a lady should say that Jesus is her Lord although he is just one of Allah's slaves."
Qariba,
The daughter of Abi Umaiyya, was the wife of 'Umar bin Al-Khattab. 'Umar divorced her and then Mu'awiyya bin Abi Sufyan married her. Similarly, Um Al-Hakam, the daughter of Abi Sufyan was the wife of 'Iyad bin Ghanm Al-Fihri. He divorced her and then 'Abdullah bin 'Uthman Al-Thaqafi married her.