In Shiite literature The Minor Occultation (Arabic: غيبة الصغری) (874–941 CE) refers to early years of Imamate of Muhammad al-Mahdi who disappeared and would only contact his followers through the Four Deputies. This occultation is also called as the First Occultation (Arabic: غيبةالاولی).
During the seven years of Hasan al-Askari's Imamate, he lived in taqiyah for the Abbasid Caliphs were afraid of Shia who had reached a considerable population at the time. Besides, the Caliphs came to know that the leaders among the Shia believed that the eleventh Imam, according to numerous traditions cited by him and his forefathers, would have a son who was the promised Mahdi. So the caliphs of the time had decided definitely to put an end to the Imamate in Shiism once and for all.
In such circumstances, Al-Mahdi gained the Imamate after the death of Hasan al-Askari in 874. In some narrations it is mentioned that Muhammad Al-Mahdi prayed Salat al-Janazah over his corpse and then he went into Minor Occultation from the authorities of the `Abbasid caliphate as a precaution.
During the Minor Occultation Al-Mahdi connected with Shiites by his Four Deputies. When believers faced difficulty, they would write their concerns and send them to his deputy. The deputy would receive the decision of the Imam, endorse it with his seal and signature, and return it to the concerned parties. The deputies also collected zakat and khums on his behalf. For the Shia, the idea of consulting a hidden Imam was not something new, because the two prior Shia Imams had, on occasion, met with their followers from behind a curtain.