")[3] Nonetheless, al-Sulayhi converted to Ismailism, a branch of Shia Islam, after coming under the influence of the da'i ("missionary") Amir al-Zawahi.
Starting in 1032, he served as amir al-hajj, leading and protecting the annual hajj ("pilgrimage") caravan to Mecca through Yemen and Asir's rough terrain.
He continued in this capacity for 15 years, lecturing groups of pilgrims, including regional Muslim leaders of various ranks, on Ismaili thought on behalf of the Fatimid caliphs.
After being temporarily besieged by local horsemen, he proceeded to build a large fort at the mountaintop and amassed a huge force of fighters from his tribe and their allies.
[7] Establishing his capital at Sana'a and maintaining his fortress in Masur, al-Sulayhi entered into a prolonged conflict with the Najahids, an Ethiopian ex-slave dynasty based in Zabid.
[8] Historian Ibn Khalikan states al-Sulayhi sent a female slave to the Najahid leader Abu Said Najah as a peace offering with the real intent of killing him.
Muslim historian Ibn al-Athir stated that once al-Sulayhi obtained Fatimid legitimacy he "embarked on the conquest of the country and toppled the fortresses one after the other with incredible speed.
[11] Because of his Shia religion and his descent from the Hamdani tribe which was linked to the era of Sheba he was able to impose his rule over Yemen with popularity and thus relative ease.
[5] Regarding al-Sulayhi's conquest of Mecca, Ibn al-Athir stated, "He put an end to injustice, reorganized the supply system, and increased the acts of beneficence.
[14] In 1066 al-Sulayhi made the hajj pilgrimage to Mecca with a large caravan that included Asma and the entourage of her court, all of the emirs of the Sulayhid principalities in Yemen, and 5,000 Ethiopian (Abyssinian) soldiers.
In response, al-Sulayhi dispatched a force of 5,000 Ethiopian horsemen to protect the caravan and kill the Najahid brothers if they were confronted on the route to Mecca.
Following the latter's death and the execution or imprisonment of his family members and emirs, al-Ahwal enlisted al-Sulayhi's Ethiopian army and with them marched back toward Zabid and successfully wrested control of the former Najahid city.
Al-Mukarram, who had succeeded al-Sulayhi as sultan, was in a state of disarray until his mother Asma had a letter secretly delivered to him chastising him for his weakness and inciting him to free her.