On the evening of 22 May 1844, in the Iranian city of Shiraz, a young merchant named Siyyid Ali Muhammad Shirazi declared to a visiting Shaykhi scholar, Mulla Husayn, that he was the Bab, the Gate, a title carrying messianic significance within the Shaykhi school of Twelver Shia Islam from which both men came. Mulla Husayn had traveled to Shiraz seeking a figure many Shaykhis expected to appear, and accounts of the meeting describe him testing Ali Muhammad's claim with detailed theological questions before accepting it, becoming the Bab's first follower.
Over the following months and years, the Bab gathered eighteen initial followers, known as the Letters of the Living, who fanned out to spread word of his claim across Iran and beyond, and he began producing an extensive body of writings elaborating his teaching, including a new book of laws intended to supersede portions of Islamic religious law. His movement attracted increasing numbers of followers, and increasing hostility from both the Iranian clergy, who regarded his claims as heretical, and the state, which came to view the growing Babi movement as a political threat.
The Bab was arrested and confined under increasingly severe conditions in the years following his declaration, moved between several fortresses in remote parts of Iran, while his followers continued to spread his teaching despite mounting persecution that would culminate in his execution in 1850.