Following Muhammad's death in June 851, the caliph al-Mutawakkil assigned Yusuf his father's offices as head of security and governor of Adharbayjan and Arminiyah.
[1] Upon his arrival in Arminiyah, Yusuf was forced to deal with the rebellion of the Armenian prince Bagrat II Bagratuni, who sought to gain control of the country.
He was able to neutralize Bagrat by seizing and sending him to the caliph in Samarra, but this act greatly angered the Armenian patrikioi who swore to kill him in retaliation.
The patrikioi proceeded to wipe out the garrisons that Yusuf had stationed in the rural districts of the province; they also sent encouragement and aid to the mountain dwellers of Sasun for them to attack the governor.
The Armenians then plundered his camp, while the noncombatants were ordered strip naked and set out in the snow; most of these soon died from the cold or lost their fingers to frostbite.