Sheikh Hassan Ahmed Abdel Rahman Muhammed al-Banna October 14, 1906 – February 12, 1949), known as Hassan al-Banna, is an Egyptian schoolteacher and imam, best known for founding the Muslim Brotherhood, one of the largest and most influential Islamic revivalist organizations.

Al-Banna's writings mark a watershed in Islamic intellectual history by presenting a modern ideology based on Islam.

Al-Banna considers Islam to be a comprehensive system of life, with the Quran as the only acceptable constitution.

He calls for Islamicization of the state, the economy, and society.

He declares that establishing a just society requires development of institutions and progressive taxation, and elaborates an Islamic fiscal theory where zakat will be reserved for social expenditure in order to reduce inequality.

Al-Banna's ideology involves criticism of Western materialism, British imperialism, and the traditionalism of the Egyptian ulema.

He appeals to Egyptian and pan-Arab patriotism but rejects Arab nationalism and regards all Muslims as members of a single nation-community.

The Muslim Brotherhood advocates gradualist moral reform and has no plans for a violent takeover of power.

The "Jihad of the spirit"―self-initiated productive work aimed at bettering the conditions of the Islamic community―is a significant part of their ideology.

Under al-Banna's leadership, the organization embarks on a wide-ranging campaign of social engagement; they especially emphasize public health improvements.

Following the abolition of the caliphate in 1924, al-Banna calls on Muslims to prepare for armed struggle against colonial rule; he warns Muslims against the "widespread belief" that "jihad of the heart" is more important than "jihad of the sword".

He allows the formation of a secret military wing within the Muslim Brotherhood, which takes part in the Arab-Israeli conflict.

Al-Banna generally encourages Egyptians to abandon Western customs; he argues that the state should enforce Islamic public morality through censorship and application of hudud corporal punishment.

Nonetheless, his thought is open to Western ideas and some of his writings quote European authors instead of Islamic sources.

Al-Banna is assassinated by the Egyptian secret police in 1949.

His son-in-law Said Ramadan emerges as a major leader of the Muslim Brotherhood in the 1950s.