Ali ibn Abi Talib

Ali ibn Abi Talib was born in Mecca around 600, son of the Prophet's protector-uncle Abu Talib, and raised from childhood in the Prophet's own household. The sira literature counts him the first male — a boy of about ten — to accept Islam. On the night of the hijra it was Ali who slept in the Prophet's bed to cover his departure, as Ibn Hisham records, remaining behind to return the goods held in trust before following to Medina. There the Prophet gave him Fatima, his daughter, in marriage; their sons Hasan and Husayn are the Prophet's only continuing line.

He fought at Badr, Uhud, the Trench, and nearly every engagement of the Medinan decade, and at Khaybar the collections of al-Bukhari and Muslim record the Prophet's words: "I shall give this banner to a man who loves God and His Messenger, and whom God and His Messenger love" — and the banner was Ali's. At Ghadir Khumm in 632, returning from the farewell pilgrimage, the Prophet took his hand and declared, "Whoever I am mawla to, Ali is his mawla" — an event transmitted in Sahih Muslim and the Musnad of Ahmad, whose intended meaning the two traditions have read differently ever since.

Through the caliphates of Abu Bakr, Umar, and Uthman he served as counselor and judge while pressing no public claim. Elected caliph in the chaos after Uthman's murder in 656, he inherited a community already at war with itself, moved his capital to Kufa, and fell in January 661 (Ramadan 40 AH) to the poisoned sword of the Kharijite Ibn Muljam while praying in its mosque. The dominant tradition places his grave at Najaf, today one of the great shrine cities of the Muslim world.

Ali's caliphate was the first fitna — the community's first civil war — and his five years of rule were a continuous struggle to hold a legitimate order together over the unresolved question of Uthman's blood. He inherited the murderers he was expected to punish embedded in the very army he needed, governors who refused his authority, and senior companions who took the field against him. After the arbitration at Siffin, a faction of his own army — the Khawarij — seceded, declaring judgment belongs to God alone, and it was one of them who killed him.

The sources also preserve his personal austerities as a ruler at war: the histories and the Nahj al-Balagha's letters show him refusing treasury favors to his own brother Aqil, patching his garments, and instructing his tax officials that the weak must never fear them nor the strong count on them. His was, the tradition transmits, a rule that would not purchase peace at the price of what he held just — and that refusal defined both his struggle and his end.

More of Ali's speech survives than of any companion, gathered above all in the Nahj al-Balagha ("The Peak of Eloquence"), compiled in the tenth century by al-Sharif al-Radi from earlier transmissions — revered in Shia Islam and admired across Sunni letters as a summit of Arabic prose. Its most cited document is his letter of instruction to Malik al-Ashtar, appointed governor of Egypt: a complete ethic of government — "people are of two kinds: your brothers in faith or your equals in creation" — treating taxation, judges, the army, the poor, and the ruler's own soul.

The hadith collections preserve the Prophet's testimonies about him beyond Khaybar: "You are to me as Aaron was to Moses, except that there is no prophet after me," recorded by al-Bukhari and Muslim at the expedition of Tabuk. The report "I am the city of knowledge and Ali is its gate," transmitted by al-Tirmidhi and others, has been variously graded by hadith critics — cherished in Shia and Sufi tradition, debated in Sunni rijal scholarship. His juristic rulings, transmitted through Kufa, fed every later school; both traditions transmit Umar's saying that Ali was the best judge among them.

In the Prophet's wars he was the standard-bearer and champion: the duels of Badr, the defense at Uhud when the ranks broke, the killing of Amr ibn Abd Wudd at the Trench when no other would answer him — the sira transmits the army's cry "there is no sword but Dhu'l-Faqar and no hero but Ali" — and the taking of Khaybar's fortress.

As caliph his battles were against fellow Muslims, and the tradition has never ceased weighing them. At the Battle of the Camel near Basra (656) he defeated the force gathered around Aisha, Talha, and al-Zubayr demanding vengeance for Uthman; Talha and al-Zubayr died, and Ali escorted Aisha honorably back to Medina — al-Tabari preserves the accounts. At Siffin (657) he fought Mu'awiya's Syrians to the edge of victory until Qurans were raised on lances and the armies forced arbitration; the arbitration's failure broke his coalition. At Nahrawan (658) he destroyed the Kharijite secession, the victory that recoiled upon him with Ibn Muljam's blade. He is remembered, in the classical juristic literature, as the precedent for how rebels among Muslims are to be fought: without pursuit of the fleeing, execution of prisoners, or plunder of property.

Ali is the axis of Islam's founding dispute. Shia Islam holds that the Prophet designated him at Ghadir Khumm and elsewhere as his successor and first Imam, that the caliphates before his were departures from that appointment, and that legitimate guidance continued in his line through Hasan and Husayn. Sunni Islam reveres him as the fourth of the rightly-guided caliphs, reads Ghadir Khumm's mawla as love and allegiance rather than political appointment, and holds the order of the first four caliphates to be the order of their merit. Both positions rest on documented transmissions; the difference is the oldest standing disagreement in Islam, and it is presented here as such.

Within his caliphate, the arbitration at Siffin remains the debated decision — accepted by Ali under his army's compulsion, then held against him by the very faction that had compelled it. The Khawarij's takfir of Ali, and his response distinguishing rebellion from unbelief, became the tradition's founding case on extremism. After his death, al-Tabari records, the public cursing of Ali from Umayyad pulpits continued for decades until Umar ibn Abd al-Aziz ended it — a documented wrong that both traditions came to repudiate.

No figure after the Prophet is revered across more of the Islamic world in more ways: to Sunnis the fourth Rashidun caliph, gate of judicial wisdom, and knight of Islam's battles; to Shia Islam the first Imam, wasi of the Prophet, and fountainhead of the Imamate; to nearly every Sufi order, the first link after the Prophet in the chain (silsila) of spiritual transmission. The shrine city of Najaf that grew over his grave is, with Karbala, the heart of Shia sacred geography and scholarship to this day.

Through Hasan and Husayn he is the ancestor of the sayyids and sharifs — the Prophet's lineage across every Muslim land, from Moroccan and Jordanian royal houses to countless scholarly families. The Nahj al-Balagha stands in Arabic letters beside the greatest prose ever written in the language, and his letter to Malik al-Ashtar is still cited — including by modern jurists and even at the United Nations — as a classical charter of just administration. His sons' fates — Hasan's treaty and Husayn's death at Karbala — carried his cause into the permanent conscience of Islam.