His inauguration

Al-Ḥākim's father had intended the eunuch Barjawan to act as regent until Al-Ḥākim was old enough to rule by himself. Ibn 'Ammar and the Qadi Muhammad ibn Nu'man were to assist in the guardianship of the new caliph. Instead, al-Hasan ibn 'Ammar (the leader of the Kutama) immediately seized the office of wasīta "chief minister" from 'Īsa ibn Nestorius. At the time the office of sifāra "secretary of state" was also combined within that office. Ibn 'Ammar then took the title of Amīn ad-Dawla "the one trusted in the empire". This was the first time that the term "empire" was associated with the Fatimid state.