Mullá Husayn  Mullá Husayn (1813–1849) ( Mulláh Hossein Boshru'i), also known by the honorific Jináb-i Bábu'l-Báb ("Gate of the Gate"), was a Persian religious figure in 19th century Persia and the first Letter of the Living of the Bábí religion. He was the first person to profess belief in the Báb as the promised Mahdi of Islam and a Manifestation of God, founding a new independent religion. The title of Bábu'l-Báb was bestowed upon him by the Báb in recognition of his status as the first Bábí. As a young man Mullá Husayn studied Usuli Shia theology, becoming an authorized member of the Shia clerical order at the age of 21. He later became a follower of the millenarian Shaykhi school, studying under its leader Siyyid Kazim Rashti and traveling to debate prominent Usuli clerics to gain support for Rashti's teachings. After Rashti's death, Mullá Husayn led a group of Shaykhis who traveled in search of the Mahdi. On 22 May 1844, in Shiraz, Mullá Husayn became the first person to profess belief in the Báb as the Mahdi, and the first follower of the Báb's religion, known as Bábism. He was appointed as the first of the Báb's apostles, called the Letters of the Living. The anniversary of his conversion is celebrated annually as a holy day in the Baháʼí Faith. As a Letter of the Living he served as a prominent Bábí evangelist and leader. His travels and public preaching were instrumental in spreading the religion throughout Persia, allowing him to come into contact with many prominent clerics and government officials, including Baháʼu'lláh and Mohammad Shah Qajar. He is often mentioned in Baháʼí literature as a paragon of courage and spiritual excellence. He led the Bábí combatants at the Battle of Fort Shaykh Tabarsi, and was killed in that battle on February 2, 1849. Mullá Husayn is regarded as a significant martyr in Bábism and the Baháʼí Faith and accorded a high spiritual station in both religions as the first to believe in the Báb and a prominent participant in the perceived fulfillment of many elements of Islamic eschatology.