OPEC was founded in Baghdad in 1960 by five oil-producing countries.
The founding members were Iran, Iraq, Kuwait, Saudi Arabia and Venezuela. They created the organization to coordinate petroleum policies and strengthen members’ bargaining position with international oil companies.
OPEC’s headquarters first operated in Geneva, Switzerland, before moving to Vienna, Austria, in 1965. Its influence grew as member countries increased control over production and nationalized parts of their petroleum industries.
OPEC is sometimes confused with OPEC+, a later cooperation framework that includes several non-OPEC producers, notably Russia. OPEC itself is the original intergovernmental organization, while OPEC+ is a broader production-coordination arrangement.