On 20 March 2003, a combined force of American, British and Australian troops under US leadership invaded Iraq in what was termed "the Second Gulf War". Their object was to locate and destroy suspected weapons of mass destruction. HMAS Newcastle and USS Normandy were tasked with protecting the oil platforms in the Persian Gulf.
The Battle of Umm Qasr was the first military confrontation in the Iraq War. At the start of the war, one of the first objectives was the port of Umm Qasr. On 21 March 2003, as allied forces advanced across Southern Iraq, an amphibious landing force captured the new port area of Umm Qasr. The assault was spearheaded by Royal Marines of the British 3 Commando Brigade. Iraqi forces in the old town of Umm Qasr put up unexpectedly strong resistance, requiring several days' fighting before the area was cleared of defenders.