At the outbreak of the war the 1st Battalion was in Karachi, India, and were involved with internal security duties. In April 1941 350 officers and men were airlifted to Iraq and took part in action at the RAF air station at Habbaniya against pro-German Iraqi forces under Raschid Ali who had just come to power following a coup d'etat. Between 19th and 22nd May 1941 the battalion saw action at Fallujah which defeated the Iraqis and opened the road to Baghdad. The battalion remained in Iraq as part of the occupying force until May 1942 when it was transferred to the Western Desert. In June 1942 the Battalion was on the Libyan-Egyptian Frontier, until ordered to fall back to Mersa Matruh. On 29th June the Battalion was ordered to break out towards Fuka airfield and El Alamein. Many were killed or wounded during the withdrawal. Those remaining left Alexandria for Cyprus on 17th August on board the troop ship Princess Marguerite which was torpedoed en-route. The battalion eventually reached Cyprus as was made up to strength with men from the 1st Battalions of the South Wales Borderers and the Duke of Cornwall's Light Infantry. After training in Cyprus, Syria and Palestine the battalion was sent to the Greek island of Leros on 5th November 1943. Deprived of air cover the King's Own, along with three other infantry battalions, were subject to a German airborne and sea landing on 12th November. After only a few days of fierce fighting the island was forced to surrender. Only a handful of men escaped - more than fifty were killed and an unknown number wounded and taken prisoner. The handful who escaped made it to Palestine and what was left of the 1st Battalion was merged with the 8th Battalion King's Own, and the unit retained the title of the 1st Battalion. The new 1st Battalion landed in Italy on 28th March 1944 and operated as part of the 10th Indian Division. They were in the Tiber Valley in June, captured the village of Montone in July and took part in a night attack which opened the road to Citta di Castello. In October 1944 the Battalion fought in the Adriatic sector, taking San Martino, followed by heavy fighting to secure and retain Pideura Ridge, west of Faenze in December 1944. The battalion was resting at Ferrar in Northern Italy when the campaign ended on 2nd May 1945.