Ayman al-Zawahri started his activism by joining the Muslim Brotherhood in 1966, at age 15. In the 1970s, he helped found Al-Jihad when he felt that the Muslim Brotherhood was too tame.. However, after being acquitted of charges of participating in the assassination of Egypt’s President Sadat, he left Egypt in 1986 and travelled to Saudi Arabia, Pakistan, Sudan, and Afghanistan. In this later destination, he came into close contact with Osama Bin Laden, a wealthy Saudi who became a prominent organizer and financier of the Arab volunteers. These volunteers traveled to Afghanistan to fight against the Soviet invasion of the country which started on December 25, 1979. Bin Laden conceived of creating Al-Qaeda as an organizational frame for the Mujahideen after the war.
When al-Zawahri and Bin Laden decided to join forces, their two organizations, Islamic Jihad and Al-Qaeda, united to form Qaedat al-Jihad (Base of Jihad), widely known as simply Al-Qaeda.