Al-Mu'ayyad Muhammad, the son of Imam al-Mansur…

Al-Mu'ayyad Muhammad, the son of Imam al-Mansur al-Qasim, who had restored the Zaidi imamate and begun the cumbersome process of conquering back Yemen from the Ottoman occupiers, had taken the reins of government from his father in 1620, at which time much of the highland was in Zaidi hands, and an uneasy truce obtained with the Turks.

The population in and around Sa'dah in the north in 1622 had refused to pay taxes to the imam.

Muhammad then sent his brother Saif al-Islam al-Hasan who put down the revolt.

Al-Hasan, however, had found means to win the confidence of the locals through reforms, and was appointed governor on behalf of the imam.

Through this act of delegation of power to a relative, the power of the Qasimid family had been confirmed in the north.

Muhammad decides in 1626, however, to break with them.

The tribes of northern Yemen respond enthusiastically to his call, and the rising scores victories against the Turks.

Most of the lowland area of Tihamah fall to the imam's forces, and San'a is besieged.

The Ottoman difficulties are aggravated by the attacks of Shah Abbas of Persia on Turkish positions in Iraq.