Azal had been appointed by the Bab head of the Babi community and preserver of the sacred text, and in Baghdad he exercised this function in an indirect style, keeping himself secluded (in a form of ghayba) while communicating with the faithful through a number of intermediaries. It was not long before his brother Ḥusayn 'AlI, acting as his chief representative, came to occupy the position of de facto chief of the exile community. In the early 1850s, Babism had been plagued by a succession of claimants to some sort of theophanic authority, but by the 1860s most of these individuals were either dead or had recanted their claims. Increased attention thus began to be focussed on Bahā' Allāh, who at first denied any status for himself but in the end claimed to be the return of the Imām Ḥusayn and finally 'he whom God shall manifest', the messianic figure of the late Babi scriptural texts. There is evidence that he made a declaration to this effect to a selected group of Babis in 1863 on the eve of his further banishment to Istanbul and, a few months later, Edirne.
It was in 1866 in Edirne that the break occurred between Husayn 'Ali and his followers (henceforth known as Baha'is) on the one hand and Şubḥ-I Azal and his adherents (Azalis) on the other. With the exile in 1868 of Azal to Cyprus and Bahā' Allāh to Acre in Palestine, the breach within the Babī ranks became absolute. For the remainder of his life, Bahā' Allāh stayed in Acre or its vicinity, during which period he composed the bulk of his writings and organized his own religious system, dependent on but distinct from both Babism and Shi'i Islam. Regarded by his followers as the supreme manifestation of the divinity (and by some as its incarnation), he exercised total authority and became increasingly remote, in contrast to the years in Baghdad, when his popularity had stemmed precisely from his accessibility to and constant contact with both Babis and the general public.
(Baha'u'llah: The King of Glory by Hasan Balyuzi, Review by: Denis MacEoin)