A doctor by profession, al Qaeda chief Ayman al-Zawahiri was born in 1951 in a prosperous family in Cairo, Egypt.
Rejecting his family fortune, at the age of 14, al-Zawahiri had joined the Muslim Brotherhood.
Though, al-Zawahiri met Osama bin Laden in Jeddah, it was in Pakistan where two worked closely together.
Pakistan has always held a special place for al-Zawahiri, where he first arrived in 1985 to work as a surgeon at a Red Cross hospital in Peshawar.
Drawn by bin Laden, then running a base for mujahideen called Maktab al-Khadamat (MAK), al-Zawahiri started working as his personal physician.
While al-Qaeda has been active in Pakistan for year, it was in 2007 that a direct link was found between al-Zawahiri, then the deputy head of the terror outfit and its attacks on Pakistan.
The outfit’s presence came to light after Pakistan’s military ruler General Parvez Musharraf laid siege of the jihadists holed inside Islamabad’s Lal Masjid.
Earlier in 1995, al-Zawahiri's Islamic Jihad had bombed the Egyptian Embassy in Islamabad.
Within three years, Islamic Jihad and al-Qaeda had merged and al-Zawahiri became bin Laden’s deputy.
After bin Laden died in a raid by US Navy SEALs in 2011, al-Zawahiri took over the reins of al-Qaeda.
Since then he has remained largely in the background but with the ISIS stealing some of al-Qaeda's thunder, it is believed that al-Zawahiri is now trying to re-assert himself and his organization’s role in the region.