Samuel tried to establish self-governing institutions in Palestine, as required by the mandate, but was frustrated by the refusal of the Arab leadership to co-operate with any institution which included Jewish participation.[10] When Grand Mufti of Jerusalem Kamil al-Husayni died in March 1921, High Commissioner Samuel appointed his half-brother Mohammad Amin al-Husayni to the position. Amin al-Husayni, a member of the al-Husayni clan of Jerusalem, was an Arab nationalist and Muslim leader. As Grand Mufti, as well as the other influential positions that he held during this period, al-Husayni played a key role in violent opposition to Zionism.