Five countries founded OPEC in Baghdad in September 1960
OPEC was founded at a conference in Baghdad held from 10 to 14 September 1960, where delegates from five countries signed the founding agreement. Four of the five came from the Middle East, and the host was one of them. The fifth came from Latin America, and one of its ministers was a driving force behind the new organisation. The list is fixed: countries joining or leaving OPEC now cannot change who founded it.
Name them all.