Opec, or the Organisation of Petroleum Exporting Countries, was formed by joint agreement at the Baghdad Conference by Iran, Iraq, Kuwait and Saudi Arabia. The cartel is intended to counterweight the influence of the big seven western oil companies (the so-called "Seven Sisters") which dominated the global petroleum business at that time.

Opec becomes a household word in western nations as oil prices surge to unprecedented levels in the wake of the Arab oil embargo of industrialised countries, following the October war between Israel and its Arab neighbours.

The second oil shock of the decade hits the world as a result of widespread disruption of the Iranian oil industry after the Islamic revolution.

After rising steadily in the early years of the decade, oil prices suddenly collapse after widespread Opec cheating on oil quotas forces Saudi Arabia to slash exports from some 7m barrels a day to 2.6m barrels / day. Saudis efforts to reclaim market share causes a deep slump in the price of oil globally.

Panic buying sends oil prices soaring after Iraq's invasion of Kuwait, but a surge in Saudi output a the brief use of Western Strategic Oil stocks prevents a fourth oil price crisis.

Oil prices collapse to under $10 a barrel as a result of chronic Opec quota cheating and the economic collapse in Asia.

Opec responds with a series of deep production cuts which reverse bearish sentiment and trigger a slow, steady rise in oil prices.

Fears that the world will be starved of sufficient oil supplies to maintain the economic expansion and emerging bottlenecks throughout the worlds oil industry drives prices to a series of fresh 10-year peaks. Three Opec production increases fail to quell fears, prompting the US to order the release of strategic petroleum stocks for only the second time.