Iran–Iraq War

The Iran–Iraq War, also referred to as the First Gulf War (Gulf War I) and the First Imposed War, began with the Iraqi invasion of Iran in September 1980. After eight years of conflict, both countries accepted a ceasefire deal brokered by the United Nations, which became effective in August 1988. The war caused around 500,000 deaths (excluding numbers from the related Anfal campaign), making it the deadliest conventional war ever fought between regular armies of developing countries.