He belonged to the Qasimid family which claimed descent from Muhammad, who dominated the Zaidi imamate of Yemen in 1597–1962.
Al-Mansur al-Husayn II retained control over San'a but found reason to pay allegiance to an-Nasir Muhammad.
Coffee had hitherto been almost solely produced in Yemen, and the rising prices provided great incomes for the country.
In 1731 the imam's agents in the Aden area were murdered by a chief in Lahej, Fadl bin Ali al-Abdali.
The governor in Mocha had the habit of purchasing goods from foreigners and, instead of paying, promise to deduct future duties.