12The first two secretaries general were Chairs of the Board of Governors in OPEC, and ex-officio secretaries general. The functions of the two positions were separated prior to the appointment of Secretary General Lutfi, in May 1965.
12345The first five secretaries general were chosen to represent OPEC's founding countries in alphabetical order, and then each of the next eight members took their turn. Only Angola, the last country to join OPEC (2007), has not yet held the position.
12345Due to political disagreements over the Secretary General position during the Iran–Iraq War, OPEC between mid-1983 and mid-1988 was led by Presidents with a mandate to supervise the Secretariat.