It has been observed that a group of Mubarakiyya in Kufa among the Ismaili orbit believed in the Mahdism of Imam Muhammad bin Ismail, anticipating his return, which had never been promulgated by the official dawa. Granted that it was the propaganda of the Ismaili dawa, there would hardly be a place left for the Imams for them in the line of Muhammad bin Ismail. This small Ismaili group was expecting the return of the Imam, and a dai Hussain al-Ahwazi had also a leaning towards them. He had gone to southern Iraq for propaganda and procured large converts.
Nuwayri (677-732/1279-1332) writes in "Nihayat al-Arab" (ed. M. Jabir A. al-Hini, Cairo, 1984, p. 189) that, "Hussain al-Ahwazi also converted Hamdan bin al-Ash'ath al-Qarmati to Ismailism in 261/874." Hamdan al-Qarmat started to reveal Ismaili doctrines and the return of Muhammad bin Ismail to the villagers and brought them in the fold of Ismailism. When Hussain al-Ahwazi died, Hamdan al-Qarmat continued his mission with his brother-in-law Abdan bin al-Rabit as his deputy. He increased his influence among the Arab and Nibati tribes in Kufa and appointed Abdan bin al-Rabit and Zikrawayh bin Mihrawayh as his assistants.
The southern Iraqian term karmitha or karmutha, unknown to Arabic elsewhere, implied an agriculturist or a villager. Later on, it was arabicised into qarmat or qarmatuya which has different meanings. In Arabic the root qarmat means "to walk" or "make short steps" and thence "to write closely" etc. Another view suggests that it was an Aramaic nickname, meaning "short-legged" or "red-eyed", since Hamdan possessed both peculiarities, therefore, he was widely known as Hamdan al-Qarmat. The converts of Hamdan al-Qarmat also became known as "Qarmatians" - a regional identity of a group of the Ismailis in southern Iraq.
Hamdan al-Qarmat maintained correspondence with the Ismaili dais at the headquarters in Salamia, and was quite unknown about the hidden Imams of the era of concealment. In 286/899, Hamdan received a direct letter from Imam al-Mahdi from Salamia, suggesting certain changes. He became surprised to receive a letter from an Imam, and consequently, he sent his envoy Abdan to Salamia to investigate. It was only at Salamia that Abdan found that al-Mahdi had succeeded to the Imamate, following the death of Imam Radi Abdullah. Abdan interviewed with the Imam without procuring result. He returned back and reported to Hamdan al-Qarmat that instead of the Mahdiship of Muhammad bin Ismail, the new leader claimed the Imamate for himself in the line of Muhammad bin Ismail.
Hamdan, thus considered it as drastic deviations, and assembled his subordinate dais, and renounced his allegiance from the central leadership of Salamia and officially abjured Ismailism. He also ordered his dais to suspend the mission in their respective districts. Soon afterwards, Hamdan went to Kalwadha, near Baghdad and was never heard of again. Abdan was also murdered in 286/899 at the instigation of Zikrawayh. Soon, however, Isa bin Musa, a nephew of Abdan, rose to lead the Qarmatians, and they were subdued by the Abbasid commander, Harun bin Gharib.
Finally, the leadership came to the hands of Zikrawayh, who dispatched his three sons, viz. Yahya, Hussain and Ali to Syria. They seized Hams, Hammah etc., and marched towards Salamia, where Imam al-Mahdi resided. Tabari (d. 310/922) in his "Tarikh al-Rusul wa'l Muluk"(ed. de Goeje, Leiden, 1879-1901, 3rd vol., p. 2226) simply writes the rise of Zikrawayh around 289/901 and their massacre in 290/902. They killed many relatives of the Imam and sacked the town, taking away treasures of the Imam. Al-Mahdi had left Salamia before the coming of the Qarmatians. Finally, the Abbasid forces reached Salamia and subdued their rising. Yahya and Ali had been killed in the encounter, and Hussain was taken prisoner and beheaded in Baghdad. When Zikrawayh knew the death of his sons, he proceeded towards Kufa and captured Basra, and threatened the Abbasids near Baghdad. He was also repulsed in 294/906, causing an end of the Qarmatian power in Iraq and Syria.