Uthman came from the Umayyad clan of Quraysh, one of the richest trading families of Mecca, and he kept his fortune after converting to Islam early, in the first years of the movement. That wealth made him one of its most important early patrons. Tradition credits him with buying the well of Rumah to give the young community of Medina fresh water, with equipping a large part of the "Army of Hardship" that marched to Tabuk, and with paying to enlarge the Prophet's Mosque. It is the background to his epithet al-Ghani, "the Generous."
His other epithet, Dhu al-Nurayn, "Possessor of the Two Lights," records something rarer: he married two of the Prophet's daughters, Ruqayyah and then, after her death, Umm Kulthum. No other man is remembered as having done so, and it bound him closely to Muhammad's household. Among Sunnis he is counted the third of the four Rashidun, the "rightly guided" caliphs whose rule is held up as a model, and he is one of the ten Companions promised paradise. His standing in Shia memory is far more critical, and the reasons for that belong to the story of how his caliphate ended.