He has held this position of Imam, under the title of Aga Khan IV, since 11 July 1957, when, at the age of 20, he succeeded his grandfather, Sir Sultan Muhammad Shah Aga Khan III.
Ia memegang jabatannya sebagai Imam, dengan gelar Aga Khan IV, sejak 11 Juli 1957, dimana, pada usia 20 tahun, ia menggantikan kakeknya, Sir Sultan Muhammad Shah Aga Khan III.