Dhu'ayb began his career as a member of the pro-
Fatimid,
Musta'li daʿwa in
Yemen, and rose to become an assistant of the local chief missionary (
dāʿī), Yahya ibn
Lamak. Shortly before his death in 1126, Ibn Lamak, after consulting the
Sulayhid queen
Arwa al-Sulayhi, chose him as his successor. In 1130, following the death of the Fatimid
imam-
caliph al-Amir bi-Ahkam Allah, Musta'li Isma'ilism was split into the
Hafizi and
Tayyibi branches, with the former acknowledging the succession of al-Amir's cousin
al-Hafiz li-Din Allah, and the latter the succession of al-Amir's infant son,
al-Tayyib. In Yemen, the hitherto pro-Fatimid queen Arwa sided with the Tayyibis and broke off relations with
Cairo, while the regional dynasties of the
Hamdanids and the
Zurayids recognized al-Hafiz's claims. Until her death in 1138, Arwa effectively headed the new Tayyibi
daʿwa, and came to be regarded by the Tayyibis as
hujja, the living proof of the hidden (
satr) imam al-Tayyib. With the support of Dhu'ayb and other
dāʿīs, the queen spent most of her final years in organizing the new sect. Sometime after 1132, she appointed Dhu'ayb as
dāʿī al-muṭlaq, thus making him the head of the
daʿwa on behalf of the hidden imam. This was not an easy undertaking, as the other Yemeni rulers did not adopt Tayyibi Isma'ilism, and after Arwa's death, the Tayyibis were left without a strong patron. Nevertheless, precisely due to the establishment of an independent hierarchy, separate from both the Fatimids and the Sulayhids, the Tayyibi
daʿwa managed to not only survive both regimes, but also spread in the region. As
dāʿī, Dhu'ayb managed to convert
al-Khattab ibn al-Hasan ibn Abi'l-Hifaz, the chieftain of the
al-Hajur clan of the
Banu Hamdan tribe. A skilled warrior and notable poet and theologian, al-Khattab became Dhu'ayb's principal aide, and an important asset to the Sulayhid and Tayyibi cause, until his murder by his nephews in a dispute over control of al-Hajur in 1138. Al-Khattab was succeeded as chief assistant (
maʾdhūn) by another Hamdanid,
Ibrahim ibn al-Husayn al-Hamidi. When Dhu'ayb died in 1151, Ibrahim became the new
dāʿī al-muṭlaq. ==References==