He died at the Battle of Fort Shaykh Tabarsi, on February 2, 1849. The title of Bábu"l-Báb was bestowed upon him by the Báb. His father Hajji Mullah Abdullah was a dyer.
His mother was a poetess and known for her piety and knowledge.
Like most young boys of the era he received a haphazard education, learning a little scripture, reading, writing and basic mathematics. At the age of 12 he left school and pursued higher education, which included lessons in Persian literature and the Qur"an, whilst mastering the art of debate.
On Sayyid Kazim"s death, Mulla Husayn spent forty days secluded in prayer, after which he traveled to Bushehr and then to Shiraz. There, on 22 May 1844, he encountered the Báb, who declared to Mulla Husayn that he was the expected Qa"im.
Mulla Husayn thus became the first of the Báb"s followers.
The anniversary of this declaration is observed as a holy day by Bahá"í communities around the world.