fourth head of the Ṣafavid order of Sufi (Islamic) mystics, who sought to transform the spiritual strength of the order into political power.

Little is known of Junayd's early life except that when his father died in 1447 he became the head of the Ṣafavid order, which had its capital at Ardabīl, Iran. Because he was a minor, he was placed under the guardianship of his paternal uncle, Sheik Jaʿfar. Before Junayd's time the leaders of the Ṣafavid order were widely respected for their piety and learning. The order was “moderate” in that it was concerned more with meditation and contemplation than with temporal authority. Junayd, however, was headstrong and ambitious. He attempted to convert spiritual respect into temporal power, a policy that led to a split in the order. The moderate majority remained with Sheik Jaʿfar, and the remaining members followed Junayd. Junayd was the first Ṣafavid leader to whom the term sultan, indicative of temporal rule, was applied. The arming of his murīds (spiritual followers), who regarded him as an emanation of divinity, brought him into conflict with Jahān Shāh (d. 1467), the ruler of Azerbaijan, in northwest Iran, and resulted in the expulsion of Junayd and his followers from Ardabīl, the traditional centre of the Ṣafavid order, in 1448. The moderate wing of the order remained under the control of Jaʿfar.

Junayd then attempted to seek a new power base for his extremist wing of the order. When Sultan Murad II, the Ottoman ruler, refused him sanctuary in his domains, Junayd led his followers to Aleppo (now in Syria) but was expelled by the authorities. He next attempted to settle along the southern shores of the Black Sea. In 1456 he led an unsuccessful campaign against the Christian Greek principality of Trabzon (now in Turkey). The attack was motivated by the desire for booty and to attract new recruits to his banner. After the failure of this expedition he sought refuge with the Turkish ruler Uzun Ḥasan, who received him and allowed him to remain in the city of Amid.

Junayd married Uzun Ḥasan's sister, Khadījah Begūm. This alliance revived the fortunes of the extremist wing of the Ṣafavid order and was in line with Uzun Ḥasan's policy of supporting Sufi (mystical) orders to add legitimacy to his rule. Junayd sought an alliance with Uzun Ḥasan's Sunnite Turks, who were enemies of the Shīʿite Jahān Shāh. On leaving Amid in 1459 to retake Ardabīl, Junayd was blocked by the superior forces of Jahān Shāh. Junayd and his 10,000 troops turned north to attack the Christian Circassians in Tabarsaran (in the Caucasus region), where he was killed in an ambush. His policies of military adventurism combined with Shīʿite and Sufi piety were continued by his son, Ḥaydar, and culminated eventually in the establishment of the Ṣafavid dynasty and of Twelver Shīʿite Islam in Iran under his grandson, Ismāʿīl I.