Inwood enlisted in the Australian Imperial Force in August 1914, and along with the rest of the 10th Battalion, he landed at Anzac Cove, Gallipoli, on 25 April 1915.

During the Battle of Menin Road in September, he was involved in the elimination of a German machine-gun post and other actions, for which he was awarded the Victoria Cross.

After the war he returned to work with the City of Adelaide, and upon his death he was buried with full military honours in the AIF Cemetery, West Terrace.

[5] The 10th Battalion underwent its initial training at Morphettville, South Australia, before embarking on the troopship HMAT A11 Ascanius at Outer Harbor on 20 October.

They then boarded trains for Cairo where they entered camp at Mena in the shadow of the Great Pyramid of Giza on the following day, along with the rest of the AIF.

They embarked on the British troopship HMT Ionian on 1 March, and a few days later arrived at the port of Mudros on the Greek island of Lemnos in the northeastern Aegean Sea, where they remained on board for the next seven weeks.

[10] The brigade embarked on the battleship HMS Prince of Wales and the destroyer HMS Foxhound, and after transferring to strings of rowing-boats initially towed by steam pinnaces, the battalion began rowing ashore about 4:30 a.m.[10][11] Inwood participated in the heavy fighting at the landing,[12] and other than a short period in hospital in May, was involved in the subsequent trench warfare defending the beachhead, being promoted to lance corporal in August.

[2][13][14] The battalion underwent reorganisation and training in Egypt then sailed for France in March 1916 where it was committed to fighting on the Western Front in June.

[16] Inwood did not rejoin his battalion until 30 July, and was promoted to temporary corporal two weeks later in the wake of the 327 casualties suffered by the unit during its first major action on the Western Front, the Battle of Pozières.

[20][21] The battalion was then sent to rest and recuperate for a few weeks at a camp near Poperinge in Belgium, before returning to the front line at Hill 60 near Zillebeke in late September, having absorbed replacements.

[4][17] The battalion then returned to the front line near Gueudecourt, France, until 12 November, and was then withdrawn into rear areas until a stint in the support trenches at Flers in early December.

[24] Once Inwood returned to the battalion, it was involved in fatigue duties, then training, before moving back into the front line at Le Barque near Bazentin in mid-February 1917.

[31] Attacking the second objective along the west edge of Polygon Wood with the rest of his unit, Inwood moved forward of the friendly artillery barrage and single-handedly captured a German post, killing several enemy and taking nine prisoners.

The fighting continued over the next few days, and on the early morning of 21 September, while the battalion was consolidating, Inwood located a German machine-gun post that was causing considerable trouble for his unit.

During the evening he volunteered for a special all night patrol, which went out 600 yards in front of our line, and there – by his coolness and sound judgment – obtained and sent back very valuable information as to the enemy's movements.

He went out alone and bombed the gun and team, killing all but one, whom he brought in as a prisoner with the gun.Inwood had another two weeks' leave in the United Kingdom immediately prior to Christmas 1917,[43] during which he was invested with his VC by King George V at Buckingham Palace on 12 December.

[44] The 10th Battalion continued to rotate through front line, support, reserve and rest areas until mid-April 1918 when it travelled north by train, and was involved in an attack at Méteren on 24–25 April, during which it suffered 79 casualties.

He was repatriated to Australia along with nine other VC recipients in August 1918, to take part in a recruiting campaign on the invitation of Prime Minister Billy Hughes.

[4][51][52] Inwood returned to a hero's welcome in Broken Hill in October 1918 but at an event organised in his honour gave a controversial public speech.

[4] Newly enlisted soldiers had been hooted and jeered at by militant socialists in Broken Hill on their departure, but there is no evidence stones were thrown.

[8] No longer welcome in Broken Hill due to his comments, Inwood moved to Adelaide where he married a 23-year-old widow, Mabel Alice Collins, née Weber, on 31 December 1918.

[8] Less than a month after the outbreak of World War II, Inwood volunteered for service in the Citizens Military Forces and again enlisted as a private, although he was promoted to sergeant within a week.

[57] In 2005 Inwood's VC became the centre of considerable media and community debate with calls for it to be displayed in the Australian War Memorial's Hall of Valour.