Hazrat Usman (R.A) was a companion and son-in-law of Holy Prophet (S.A.W) and he was born in a noble family of Quraish named as “Ummayah” which was well reputed and honorable family of Makkah.His patronymic name was "Abu Amr" and father's name was "Affan bin Abul-As". He was known with the name of “Usman ibn Affan”. He was one of the few people in Makkah who knew about writing and reading.
Hazrat Usman (R.A) accepted Islam when Abu Bakr (R.A) invited him. He was one of those Muslims who accepted Islam in its early days. In spite of the fact that "Banu Hashim" was opponent to "Banu Umayyah", yet Usman (R.A) did not care and accepted Islam with his heart. When he accepted Islam as his religion, the Quraish who once adored Usman (R.A) turned into his foes. Indeed his relatives like Hakam (one of his uncles) started to think about Usman (R.A) as an enemy.
Dhun Nurain means “The man with two lights”; this title was given to Hazrat Usman (R.A) after he married with two daughters of Holy Prophet (S.A.W), one after the other.
A daughter of Holy Prophet (S.A.W) was married to son of Abu Lahb. When Holy Prophet (S.A.W) started to invite peoples to Islam, Abu Lahb forced his son to divorce Ruqayyah (R.A). Then Holy Prophet (S.A.W) married her to Hazrat Usman (R.A).
Hazrat Usman (R.A) could not attend the first battle of Badr because his wife Hazrat Ruqayyah (R.A) was very ill. She died before Muslims returned with a victory.
Narrated Ibn `Umar:
`Usman did not join the Badr battle because he was married to one of the daughters of Allah's Apostle and she was ill. So, the Prophet (S.A.W) said to him. "You will get a reward and a share (from the war booty) similar to the reward and the share of one who has taken part in the Badr battle."
(Sahih Al-Bukhari )
After the death of Hazrat Ruqayyah (R.A), Holy Prophet (S.AW) married his next daughter Hazrat Umm Kulsum (R.A) and then he was given the title of “Dhun Nurain”.