The Baháʼí–Azali split occurred when most Bábís accepted Baháʼu'lláh (Ḥusayn-ʻAlí) as the promised one of the Báb's writings, and thus became Baháʼís, leaving a remnant of Bábís who became known as Azalis, the followers of Subh-i-Azal (Mirza Yahya). The split occurred after Baháʼí founder Baháʼu'lláh made his public claim in 1863, leading to expressions of support from the majority of the Bábí community, and opposition from Subh-i-Azal, who became the leader of the remaining group.

The Báb

Siyyid ʻAlí-Muhammad was a merchant from Shiraz, Persia, who at the age of 25, claimed to be a new and independent Manifestation of God, and the promised Qá'im, or Mihdí of Islam. In his early writings he took on the title of the Báb, meaning "Gate", after a Shaykhi concept that explained he was only a, 'door', or 'gate', for a soon to come Manifestation of God, or Prophet. His followers were therefore known as Bábís. He later declared that he was not just 'a Gate to the Mihdi', or the Bab, but he was the Qa'im, or Promised One himself.

The Báb's writings had the concept of the returning messiah called, "He whom God shall make manifest". As the Báb's teachings spread, the Islamic government saw his following as a threat to the state religion. Several military confrontations took place between government and Bábí forces. The Báb was imprisoned and executed by firing squad in Tabriz on July 9, 1850.

Succession In most of his prominent writings, the Báb alluded to a Promised One, most commonly referred to as "Him whom God shall make manifest", and that he himself was "but a ring upon the hand of Him Whom God shall make manifest." The Bayán is essentially a discourse on Him whom God shall make manifest, and the Báb always discussed his own writings in the context of the coming of Him Whom God shall make manifest. Several of the Báb's writings state the coming of Him Whom God shall make manifest would be imminent.

The Báb eliminated the institution of successorship or vicegerency to his movement, and stated that no other person's writings would be binding after his death until Him Whom God shall make manifest would appear.

He did, however, appoint a nominal leader after himself. Shortly before the Báb's execution, a follower of the Báb, Abd al-Karim, brought to the Báb's attention the necessity to appoint a leader; thus the Báb wrote a certain number of tablets which he gave to Abd al-Karim to deliver to Subh-i-Azal and Baháʼu'lláh. These tablets were later interpreted by both Azalis and Baháʼís as proof of the Báb's delegation of leadership. Baháʼí sources state that the Báb did this at the suggestion of Baháʼu'lláh.

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." Multiple versions of this tablet exist, and Browne notes in his translation that this copy of the letter is actually in Subh-i-Azal's handwriting rather than the Báb's. & The Iranologist Edward Granville Browne, discussing a visit with Subh-i-Azal in Cyprus, notes that he saw the original document in the Báb's own handwriting.

In addition to the difficulties of collecting original Bábí documents at such a distance — Browne was at Cambridge — was the widespread Azali practice of Taqiyya (Dissimulation), or concealing one's beliefs. Browne appears to have been unaware of this.

Leadership and confrontation Subh-i-Azal's leadership was controversial. He generally absented himself from the Bábí community, spending his time in Baghdad in hiding and disguise; he even went so far as to publicly disavow allegiance to the Báb on several occasions. Subh-i-Azal gradually alienated himself from a large proportion of the Bábís who started to give their alliance to other claimants. During the time that both Baháʼu'lláh and Subh-i-Azal were in Baghdad, since Subh-i-Azal remained in hiding, Baháʼu'lláh performed much of the daily administration of the Bábí affairs.

Baháʼu'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. This declaration started a new phase of leadership in the Bábí community that would eventually lead to the emergence of the Baháʼí Faith as a separate movement distinct from Bábism. While in Adrianople (current-day Edirne, Turkey), Baháʼu'lláh was the clear leader of the newly established Bábí community, and a permanent break between Baháʼu'lláh and Subh-i-Azal occurred.

In 1865 Subh-i-Azal was accused of attempting to plot to kill Baháʼu'lláh. In contemporary accounts, Subh-i-Azal is reported to have tried to have Baháʼu'lláh assassinated at the hands of the barber of the local bath. The barber, Muhammad ʻAlí of Isfahán, apparently refused and spread word of the danger around the community. Baháʼu'lláh is reported to have counselled "on all patience, quietude and gentleness". This pattern was repeated when, according to the personal account of Ustád Muhammad-ʻAlíy-i Salmání, Subh-i Azal attempted to persuade him likewise to murder Baháʼu'lláh in the bath. Eventually Subh-i-Azal attempted to poison Baháʼu'lláh that left him gravely ill for a time, and left him with a shaking hand for the rest of his life. Later, followers of Azal made the counter-claim that Baháʼu'lláh had accidentally poisoned himself while trying to poison others.Mirza Aqa Khan Kirmani made this claim later in his Hasht-Bihisht. This book is abstracted in part by E.G. Browne in "Note W" of his translation of A Traveller's Narrative, (). However, due to the practice of Taqiyya (Dissimulation) among Azalis and contemporary historians recognize that: "The Azali Babis and in particular Mirza Aqa Khan Kirmani and Shaykh Ahmad Ruhi showed little hesitation in alteration and falsification of Babi teachings and history in their works." Manuchehri (1999) Smith also notes that the Baháʼí accounts of this dispute seem to be credible.

After this event in 1866 Baháʼu'lláh made his claim to be Him Whom God Shall Make Manifest public, as well as making a formal written announcement to Subh-i-Azal referring to his followers for the first time as the "people of Bahá". After his public announcement, Baháʼu'lláh secluded himself in his house and instructed the Bábís to choose between himself and Subh-i-Azal. Baháʼu'lláh's claims threatened Subh-i-Azal's position as leader of the religion since it would mean little to be leader of the Bábís if "Him Whom God Shall Make Manifest" were to appear and start a new religion. Subh-i-Azal responded by making his own claims, but his attempt to preserve the traditional Bábísm was largely unpopular, and his followers became the minority.

In 1867, Subh-i-Azal challenged Baháʼu'lláh to a test of the divine will in a local mosque in Edirne (Adrianople), such that "God would strike down the impostor." Baháʼu'lláh agreed, and went to the Sultan Selim mosque at the appointed time, but Mirza Yahya lost face and lost credibility when he refused to show up.

Eventually Baháʼu'lláh was recognized by the vast majority of Bábís as "He whom God shall make manifest" and his followers began calling themselves Baháʼís. The small minority of Bábís that followed Subh-i-Azal became known as Azalis.

Exile of community After the Bábí community was separated into two, the Azalis tried to discredit Baháʼu'lláh to the Ottoman authorities, accusing him of causing agitation against the government. While an investigation cleared Baháʼu'lláh, it did notify the government that Baháʼu'lláh and Subh-i-Azal were propagating religious claims, and may cause future disorder, and thus led to the further exile of the 'Bábí' leaders. A royal command was issued in July 1868 condemning the Bábís to perpetual imprisonment and isolation in far-flung outposts of the Ottoman Empire — Famagusta, Cyprus for Subh-i-Azal and his followers, and ʻAkká, in Ottoman Palestine, for Baháʼu'lláh and his followers.

While most of those that followed Subh-i-Azal were sent to Cyprus, some were sent to Akká, intended to serve as spies. In 1872 a few Baháʼís decided to kill the followers of Subh-i-Azal as they were causing endless difficulties to the Baháʼí community. Baháʼu'lláh strongly condemned the action, and publicly condemned the murderers as clear violators of Baháʼí law.Browne (1891) p. 370 The Ottoman authorities initially hardened the imprisonment of Baháʼu'lláh. But as Baháʼu'lláh was later exonerated by the authorities as having no connection to the murders, their imprisonment was eased.

After the split Eventually Baháʼu'lláh was recognized by the vast majority of Bábís as "He whom God shall make manifest" and his followers began calling themselves Baháʼís. By 1908 there were probably from half a million to a million Baháʼís, and at most only a hundred followers of Subh-i-Azal. Subh-i Azal died in Famagusta, Cyprus in 1912, and his followers are known as Azalis or Azali Bábis. MacEoin notes that after the deaths of those Azali Babis who were active in the Constitutional Revolution in Iran, the Azali form of Babism entered a stagnation from which it has not recovered as there is no longer any acknowledged leader or central organization. In the 2000s, estimates of the number of Azalis were no more than a few thousand. The World Religion Database estimated 7.3 million Baháʼís in 2010 and stated: "The Baha'i Faith is the only religion to have grown faster in every United Nations region over the past 100 years than the general population; Baha'i(sic) was thus the fastest-growing religion between 1910 and 2010, growing at least twice as fast as the population of almost every UN region." Baháʼí sources since 1991 usually estimate the worldwide Baháʼí population at "above 5 million".

After Baháʼu'lláh's death, leadership of the religion then passed on to ʻAbdu'l-Bahá, Baháʼu'lláh's son, who was appointed by Baháʼu'lláh, and was accepted by almost all Baháʼís. After the death of ʻAbdu'l-Bahá in 1921, the leadership of the Baháʼí community was passed on to his grandson, Shoghi Effendi, who was appointed in ʻAbdu'l-Bahá's will. The document appointed Shoghi Effendi as the first Guardian, and called for the election of the Universal House of Justice once the Baháʼí Faith had spread sufficiently for such elections to be meaningful. Shoghi Effendi died in 1957, and in 1963 the Universal House of Justice was elected. Since 1963 the Universal House of Justice has been elected every five years and remains the successor and leading institution of the religion.

There are conflicting reports as to whom Subh-i-Azal appointed as his successor. Browne reports that there was confusion over who was to be Subh-i-Azal's successor at his death. Subh-i-Azal's son, Rizwán ʻAli, reported that he had appointed the son of Aqa Mirza Muhammad Hadi Daulatabadi as his successor; while another, H.C. Lukach's, states that Mirza Yahya had said that whichever of his sons "resembled him the most" would be the successor. None appear to have stepped forward. MacEoin notes that Subh-i-Azal appointed his son, Yahya Dawlatabadi, as his successor, but he notes that there is little evidence that Yahya Dawlatabadi was involved in the affairs of the religion, and that instead he spent his time as that of secular reformer. Shoghi Effendi reports that Mirza Yahya appointed a distinguished Bábí, Aqa Mirza Muhammad Hadi of Daulatabad (Mirza Hadiy-i-Dawlat-Abadi) successor, but he later publicly recanted his faith in the Báb and in Mirza Yahya. Mirza Yahya's eldest son apparently became a Baháʼí himself.

Azali Taqiyya (Dissimulation)