Occultation (Islam) in the context of "Satr (Isma'ilism)"

Twelver Shi'ism (Arabic: اِثْنَا عَشَرِيَّة, romanized: Ithnā ʿAshariyya) is the largest branch of Shia Islam, comprising about 85% of all Shia Muslims. The term Twelver refers to its adherents' belief in the twelve successors, referred to as Twelve Imams, and their belief that the last Imam, Muhammad al-Mahdi, lives in occultation (ghayba) and will reappear as "the awaited Mahdi" (al-Mahdi al-muntazar) alongside Isa al-Masih (Jesus Christ), son of Bibi Mariam (The Virgin Mary), in order to restore justice and peace.

Twelver Shi'as believe that the Twelve Imams are divinely appointed as both spiritual and political successors to the Islamic prophet Muhammad, and that they possess special knowledge and authority to guide the Muslim community. According to Twelver theology, the Twelve Imams are exemplary human individuals who rule over the Muslim community (Ummah) with justice, and are able to preserve and interpret the Islamic law (Sharia) and the esoteric meaning of the Qur'an. The words and deeds (sunnah) of Muhammad and the Imams are a guide and model for the Muslim community to follow. As a result, Muhammad and the Imams must be free from error and sin, a doctrine known as Ismah (literally 'protection') or infallibility, and must be chosen by divine decree, or nass, through Muhammad.

The Guardianship of the Islamic Jurist (Persian: ولایت فقیه, romanized: Velâyat-e Faqih, also Velayat-e Faghih; Arabic: وِلاَيَةُ ٱلْفَقِيهِ, romanized: Wilāyat al-Faqīh) is a concept in Twelver Shia Islamic law which holds that until the reappearance of the "infallible Imam" (sometime before Judgement Day), the religious and social affairs of the Muslim world should be administered by righteous Shi'i jurists (Faqīh).

Wilāyat al-Faqīh is associated in particular with Ruhollah Khomeini and the Islamic Republic of Iran. In a series of lectures in 1970, Khomeini advanced the idea of guardianship in its "absolute" form as rule of the state and society. This version of guardianship now forms the basis of the Constitution of the Islamic Republic of Iran, which calls for a Guardian Jurist (Vali-ye Faqih, Arabic: وَلِيٌ فَقِيهٌ, romanized: Waliyyun Faqīh), to serve as the Supreme Leader of that country. Currently, this role is held by Ayatollah Khamenei.

The ghulāt (Arabic: غُلَاة, lit. 'exaggerators, extremists') were a branch of early Shi'a Islam. The term mainly refers to a wide variety of extinct Shi'i sects active in 8th- and 9th-century Kufa in Lower Mesopotamia, and who, despite their sometimes significant differences, shared several common ideas. These common ideas included the attribution of a divine nature to the Imams, metempsychosis (the belief that souls can migrate between different human and non-human bodies), a particular gnostic creation myth involving pre-existent 'shadows' (azilla) whose fall from grace produced the material world, and an emphasis on secrecy and dissociation from outsiders. They were named ghulat by other Shi'i and Sunni Muslims for their purportedly "exaggerated" veneration of Muhammad (c. 570–632) and his family, most notably Ali (c. 600–661) and his descendants, the Imams.

The ideas of the ghulat have at times been compared to those of the late antique gnostics, but the extent of this similarity has also been questioned. Some ghulat ideas, such as the notion of the occultation (ghayba) and return (raj'a) of the Imam, have been influential in the development of Twelver Shi'ism. Later Isma'ili Shi'i authors such as Ja'far ibn Mansur al-Yaman (died c. 957) and Abu Ya'qub al-Sijistani (died after 971) also adapted ghulat ideas to reformulate their own doctrines. The only ghulat sect still in existence today are the Alawites, historically known as Nusayris after their founder Ibn Nusayr (died after 868).

The Mahdi (Arabic: ٱلْمَهْدِيّ, romanized: al-Mahdī, lit. 'the Guided'), also Masih al-Mahdi (Arabic: المسيح المهدي, romanized: al-Masīḥ al-Mahdī, lit. 'the Guided Redeemer'), is a messianic figure in Islamic belief. He is comparable to the Christian idea of the return of Jesus and the Mashiach ben David in Judaism. He is believed to appear at the End of Times to rid the world of evil and injustice. He is said to be a descendant of Muhammad and will appear shortly before Jesus.

The Mahdi is mentioned in several compilations of hadith, but absent from the Quran and the two most-revered Sunni hadith collections (Sahih al-Bukhari and Sahih Muslim). As such, he plays only a marginal role in Sunni Islam and some Sunni theologians have rejected the concept of the Mahdi altogether. However, the Mahdi plays a significant role among Twelver Shias, who believe that the Mahdi is Imam Muhammad al-Mahdi, the twelfth Imam, son of the eleventh Imam Hasan al-Askari (d. 874), who is said to be in occultation (ghayba) by divine will.

The hadith of the twelve successors (Arabic: حَدِيْث ٱلْإِثْنَي عَشَر خَلِيْفَة, romanized: ḥadīth al-ithnā ʿashar khalīfa) is a widely-reported prophecy, attributed to the Islamic prophet Muhammad, predicting that there would be twelve successors after him. As there were many more rulers after Muhammad, Sunni authors have variously identified these twelve successors with some of these rulers. In Twelver Shia, these successors are instead identified with their Twelve Imams. Their last imam, Muhammad al-Mahdi, is believed to miraculously remain in occultation since 874 CE, and is expected to return in the end of times to eradicate injustice and evil.

Muhammad al-Mahdi (Arabic: محمد بن الحسن المهدي, romanized: Muḥammad ibn al-Ḥasan al-Mahdī) is believed by the Twelver Shia to be the last of the Twelve Imams and the eschatological Mahdi, who will emerge in the end of time to establish peace and justice and redeem Islam.

Hasan al-Askari, the eleventh Imam, died in AH 260 (873–874), possibly poisoned by the Abbasids. Immediately after his death, his main representative, Uthman ibn Sa'id al-Asadi, claimed that the eleventh Imam had an infant son named Muhammad, who was kept hidden from the public out of fear of Abbasid persecution. Uthman also claimed to represent Muhammad, who had entered a state of occultation. Other local representatives of al-Askari largely supported these assertions, while the Shia community fragmented into several sects over al-Askari's succession. All these sects, however, are said to have disappeared after a few decades except for the Twelvers, who accept the son of al-Askari as the twelfth and final Imam in Shia Islam, remaining in a state of occultation.