[1] Mamoun was born in Cairo, Egypt in 1894 to a father who was a leading member of the 'ulema ("religious scholars") and the imam of the Fath Mosque in the Abdin Palace.

That same year, a group of army officers deposed the monarchy of King Farouk and began a process of ending British colonial influence in Egypt.

[2] Mamoun was appointed Grand Mufti of Egypt on 28 February 1955 by the Egyptian government, succeeding Ahmed Ibrahim Mughith.

[3] In July 1964 President Gamal Abdel Nasser appointed Mamoun Grand Imam of al-Azhar.

As Grand Imam, in August, Mamoun declared in a fatwa that contraception was not in contradiction to Islamic law, provided the mechanism was legitimate and the conditions necessitated it.