Khadija bint Khuwaylid
Pious Muslims look to the life of the Islamic Prophet Muhammad and early Muslims as examples to be followed, and "several ... members of the Prophet's family and inner circle were married to their cousins." One of Muhammad's wives – Zaynab bint Jahsh was the daughter of Muhammad's aunt. However, Muhammad didn't have children with Zaynab, his children being all children of him and Khadija bint Khuwaylid, except one with Maria al-Qibtiyya. Ali, cousin of Prophet Muhammad and the forth Rashidun caliph, was married to the Prophet's daughter Fatimah.