I took some time to read...
Bahá'í/Bábí split - Wikipedia
In one of the tablets, which is commonly referred to as the "Will and Testament of the Báb", Subh-i-Azal is viewed to have been appointed as leader of the Bábis after the death of the movement's founder; the tablet, in verse 27, also appears to order Subh-i-Azal "...to obey Him Whom God Shall Make Manifest."
[6]
Bahá'u'lláh claimed that in 1852, while a prisoner in Tehran, he was visited by a "
Maid of Heaven", which symbolically marked the beginning of his mission as a Messenger of God. In 1863 as he was leaving Baghdad in the
Garden of Ridván, he made his first public declaration to be
Him Whom God Shall Make Manifest, the messianic figure in the Báb's writings, to a small number of followers.
[13] This declaration started a new phase of leadership in the Bábí community
I will suppose that this Wikipedia page has multiple authors each with their own agendas.