Shah Ismail I in the context of "Shaykh Junayd"

Qizilbash or Kizilbash were a diverse array of mainly Turkoman Shia militant groups that flourished in Azerbaijan, Anatolia, Kurdistan, the Armenian highlands, and the Caucasus from the late 15th century onwards, and contributed to the foundation of the Safavid dynasty in early modern Iran.

By the 18th-century, anyone involved with the Safavid state—militarily, diplomatically, or administratively—came to be broadly referred to as "Qizilbash". It was eventually applied to some inhabitants of Iran. In the early 19th-century, Shia Muslims from Iran could be referred as "Qizilbash", thus highlighting the influence of the distinctive traits of the Safavids, despite the Iranian shah (king) Fath-Ali Shah Qajar (r. 1797–1834) simultaneously creating a Qajar dynastic identity grounded in the pre-Islamic past.

Following their rise to power in Iran in the 16th century, the Safavid dynasty initiated a campaign of forced conversion against the Iranian populace, seeking to replace Sunni Islam, whose Shafi'i school of jurisprudence pervaded the country, as the denomination of the majority of the population.

Over the course of three centuries, the Safavids (who were Twelver Shias) heavily persecuted Sunni Muslims, Jews, Christians, and other religious groups, eventually transforming Iran into a bastion of Shia Islam. This process led to hostilities with Iran's Sunni-majority neighbours, most notably the Ottoman Empire. The Safavid campaign sought to ensure Twelver dominance among Shia Muslims, particularly with regard to Zaydism and Ismaʿilism—each of which had previously experienced their own eras of sectarian dominance.

Tahmasp I (Persian: طهماسب یکم, romanized: Ṭahmāsb or تهماسب یکم Tahmâsb; 22 February 1514 – 14 May 1576) was the second shah of Safavid Iran from 1524 until his death in 1576. He was the eldest son of Shah Ismail I and his principal consort, the Mawsillu princess Tajlu Khanum.

Tahmasp ascended the throne after the death of his father on 23 May 1524. The first years of Tahmasp's reign were marked by civil wars between the Qizilbash leaders until 1532, when he asserted his authority and began an absolute monarchy. He soon faced a long-lasting war with the Ottoman Empire, which was divided into three phases. The Ottoman sultan, Suleiman the Magnificent, tried to install his own candidates on the Safavid throne. The war ended with the Peace of Amasya in 1555, with the Ottomans gaining sovereignty over Iraq, much of Kurdistan, and western Georgia. Tahmasp also had conflicts with the Uzbeks of Bukhara over Khorasan, with them repeatedly raiding Herat. In 1528, at the age of fourteen, he defeated the Uzbeks in the Battle of Jam by using artillery.