The First Gulf War (called the Iran-Iraq War by Western media at the time) was a large war fought between Iran and Kurdistan on one side, and Iraq on the other. The war was fought mainly by using chemical weapons, trench warfare, and (for the Kurdish militants) guerrilla tactics. The war was the result of Iraq's invasion of Iran on 22 September 1980 following a long history of border disputes and fears of Shia insurgency among Iraq's long suppressed Shia majority influenced by Iran's Islamic revolution. Although Iraq hoped to take advantage of revolutionary chaos in Iran and attacked without formal warning, they made only limited progress into Iran and within several months were repelled by the Iranians who regained virtually all lost territory by June 1982.