Major crude oil price peaks have occurred in January of 1974, May of 1980, October of 1990 and July of 2008. Most of these peaks were tied to geopolitical events that severely restricted the actual or anticipated future supply of oil, particularly supplies from the Middle East.
The early 1974 price spike for crude oil was the beginning of what is generally considered an oil crisis in the 1970s. Prices continued to climb during the time after this peak, which was initiated by a combination of an Organization of Petroleum Exporting Countries embargo and declining production in the United States. Prices spiked again in a 1979 oil crisis that culminated in the peak price of May 1980. This crisis was mainly due to the results of the 1979 Iranian Revolution. The May 1980 price of $114.51 in inflation-adjusted 2015 dollars was the highest average monthly price for crude oil per barrel recorded until the peak prices that occurred in 2008.
The 1990 peak oil price was primarily driven by the lead-up to the first Gulf War, as fears of potential embargo and Iraqi control of the Kuwait oil fields drove speculation and shortage in the market. The 2008 oil peak price coincided with the beginnings of the financial panic that took place in 2008. The highest recorded average monthly price per barrel of oil of $143.71 in 2015 dollars was recorded at this time.