Uthman ibn Affan, Rashidun caliph (b. 577)
Uthman (Arabic: عثمان ابن عفان ابن أبي العاص, romanized: ʿUthmān ibn ʿAffān ibn Abī al-'Ās; c. 576 or 579 – June 656), also spelled Osman, was the third Rashidun caliph, ruling from November 644 until his assassination. He ruled for twelve years, the longest of all Rashidun caliphs, and during his reign, the Rashidun Caliphate reached its greatest extent. He is known for having ordered the compilation of the first standard version of the Quran.

Belonging to the Quraysh's aristocratic Umayyad clan, Uthman was an affluent merchant of Taif. Following his conversion to Islam in 611, he became a prominent companion of the Islamic prophet Muhammad. In 615, Uthman married Muhammad's daughter Ruqayya and following her death, to another of Muhammad's daughter Umm Kulthum. His wives having been daughters of Muhammad earned him the honorific title Dhū al-Nurayn ('Possessor of the Two Lights'). Though Uthman didn't participate in the early Muslim battles, he extensively contributed his wealth in support of the Muslims. After Muhammad's death in 632, Uthman served as a close aide to the first and second caliphs Abu Bakr (r. 632–634) and Umar (r. 634–644) respectively. On his deathbed, Umar formed a six-member committee, including Uthman, to chose the next caliph amongst themselves. Eventually, Uthman was chosen as the third caliph.

Uthman continued his predecessor's policies of centralization and expansion, but notably initiated a relatively new tax policy, and also assigned his Umayyad kinsman to prominent roles. Under Uthman, caliphate completed its conquest of Persia, and also continued its successful expansions into Byzantine territories. He was the first caliph to institute an integrated Muslim navy. Though Uthman was highly successful in expanding the caliphate, his nepotistic policies received him vehement opposition from numerous Muslims. In June 656, a group of Egyptian rebels besieged Uthman's house, and assassinated the caliph. The caliph was buried at a local Jewish cemetery, which was later extended to al-Baqi. His assassination marked the start of the First Muslim Civil War, as Uthman's brother-in-law Ali (r. 656–661) was elected the fourth caliph.

Uthman is viewed by historians to be one of the most successful caliphs. From an expansionist perspective, he is regarded as skilled in conflict management, as is evident from how he dealt with the heated and troubled early Muslim conquered territories. In Sunni Islam, Uthman is considered a devout and pious caliph, and also viewed as the third most righteous companion of Muhammad.