At-Tayyib Abu'l-Qasim

Al-Ṭayyib Abū'l-Qāṣim ibn al-Manṣūr (Arabic: الطيب أبو القاسم بن المنصور‎‎) was, according to the Mustaali sect of Isma'ilism, the twenty-first Imam and the last Caliph of the Fatimid Caliphate. Abul-Qāṣim was the son of the twentieth Fatimid Imam, al-Amir bi-Ahkami'l-Lah, who ruled Egypt from 1101-30. He was born in Cairo on Sunday, March 16, 1130 (4th Rabi' al-thani, 524 AH) and was 2 years 7 months old when his father, al-Amir, was assassinated in the night of (Thursday, October 15, 1132, 4th Dhu al-Qi'dah, 526 AH). Tayyib was reported to be about two years old at the time of al-Amir's assassination.Al-Hafiz was appointed representative Caliph on behalf of Imam Al-Tayyib. Later al-Hafiz declared himself as Imam and Caliph in 528 AH/1134 AD and Al-Tayyib was taken into hiding.

As per chronicle of Ibn al-Muyassar(d.677): "In Rabi al-awwal(of..524 AH)..Abul Qasim al-Tayyib was born to al-Amir;...Cairo was decorated..New suits of clothes were issued to the troops...at the 'aqiqa ceremony... in presence of al-Amir...child was brought in, and Chief Qadi Ibn al- Muyassar was given the honour of holding it...the palace was filled with fruits and other sweets..."

It is said that the guardian of Tayyib was Ibn Madyan, who have hidden him in a mosque Masjid ur-Rahmah. The infant son of al-Amir was supposed to carry in a basket of reeds by Abu Turab in which were vegetables (‘dishes of cooked leeks and onions and carrots’), and the baby wrapped in ‘swaddling clothes was on the bottom with the food above him, and he brought him to the cemetery and the wet nurse suckled him in this mosque, and he concealed the matter from al-Hafiz until the baby grew up and began to be called Kufayfa, “little basket.”’

According to Ṭayyibī Musta‘lid tradition, before Ṭayyib went into the Occultation, his father al-Amir had instructed Queen al-Hurrah Arwa bint Ahmad in Yemen to anoint a vicegerent after the seclusion, the Da'i al-Mutlaq, who as the Imam's vicegerent has full authority to govern the community in all matters both spiritual and temporal.

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