Iraq launched a full-scale invasion of Iran on 22 September 1980. The Iraqi Air Force launched surprise air strikes on ten Iranian airfields with the objective of destroying the Iranian Air Force. The attack failed to damage the Iranian Air Force significantly; it damaged some of Iran's airbase infrastructure, but failed to destroy a significant number of aircraft.
On 22 September, a prolonged battle began in the city of Khorramshahr, eventually leaving 7,000 dead on each side. Reflecting the bloody nature of the struggle, Iranians came to call Khorramshahr "City of Blood".
On 22 September 1980, when Saddam Hussein launched an invasion of Iran, setting off the Iran–Iraq War (1980–1988), Soleimani joined the battlefield serving as the leader of a military company, consisting of men from Kerman whom he assembled and trained.
By 30 September, the Iraqis had managed to clear the Iranians from the outskirts of the city. The next day, the Iraqis launched infantry and armoured attacks into the city. After heavy house-to-house fighting, the Iraqis were repelled.