of the newly raised 30th Battalion. He proceeded to the Sydney suburb of Liverpool, where he attended an infantry school before training at the Royal Military College, Duntroon. On 9 November, the 30th Battalion embarked for Egypt aboard the troopship HMAT A72 Beltana. Upon arrival in December, the battalion was tasked with the defence of the Suez Canal where, on 20 February 1916, Wark was promoted to captain. In June 1916, the battalion departed from Alexandria to join the British Expeditionary Force in France for service on the Western Front; they arrived at Marseilles on 23 June. The 30th Battalion's first major action began with the outbreak of the Battle of Fromelles on 19 July 1916. The unit was originally designated with providing carrying parties for supplies and ammunition during the battle, but was subsequently pulled into the fighting. Wark commanded a company during the action, until being evacuated to the 7th Stationary Hospital with a gunshot wound to his leg. He was transferred to the 3rd London General Hospital in England three days later, and moved again to the 5th Australian Auxiliary Hospital, Digswell House, Welwyn, on 7 August. Recovered by September, Wark was discharged and granted leave before returning to France and the 30th Battalion later that month. On 9 October 1916, Wark was attached to the 32nd Battalion, a position that became permanent on 18 November. The 32nd Battalion saw no major offensive action for the remainder of the year, and on 2 January 1917, Wark gained admission to the Army Infantry School. By February he was back with the 32nd Battalion, and took part in actions at Sunray Trench during March. For these, and further actions at Fromelles, Wark was recommended for the Distinguished Service Order, but the award was never made. He was promoted to major on 27 April, and in June was granted six days of leave to Paris. In late September and early October, Wark commanded a company in the Ypres sector of Belgium during the Battle of Polygon Wood. On 29 September—the first day of the battle—Wark's men successfully repelled the leading waves of a German counter-attack and, with artillery support, drove off the remainder. Over the following three days, his constant patrolling and personal reconnaissance of the German positions enabled him to ascertain when they were massing for further counter-attacks; on one occasion he dispersed the assembling German troops with rifle