"Indeed, al-Zawahiri has been active since 1966, when as a boy of 15, he was arrested for membership of al-Ilkwan al-Muslimun, the Muslim Brotherhood. The Islamic movement, committed to purging Egyptian society of foreign influences, particularly the British, was founded in 1928 by Egyptian schoolteacher Hassan al-Banna. Later outlawed, it became the catalyst for most of the militant Muslim organisations that sprang up across the Arab world."
It also seems that another person named al-Banna was busy forming another terrorist group:link here