In 1768, an alliance was formed between Zahir al-Umar, the semi-autonomous Arab sheikh of northern Palestine and Nasif al-Nassar, the preeminent Shia Muslim sheikh of Jabal Amil, the mountainous region between Mount Lebanon and Palestine.[4] Mansur was a close ally of Zahir and supported him and Ali Bey of Egypt in their rebellion against the Ottomans and occupation of Damascus. According to a later Lebanese chronicler, Mansur "much loved Zahir al-Umar and rejoiced" at his joint invasion of Syria and Palestine with Ali Bey.[5] The defeat of Ali Bey and Zahir prompted the Ottoman authorities to punish Mansur for siding with them. This consequently brought a withdrawal of confidence for Mansur from the Druze clans.[4] He was dismissed and succeeded by Yusuf in 1770.[4]