He was 24 years old, and a company sergeant-major in the Special Reserve, The Royal Welch Fusiliers, British Army, attached to the 1st Battalion, The Royal Welch Fusiliers during the First World War when the following deed took place for which he was awarded the VC. On 16 May 1915 at Festubert, France, Company Sergeant-Major Barter, when in the first line of German trenches, called for volunteers to enable him to extend our line, and with the eight men who responded, he attacked the German position with bombs, capturing three German officers, 102 men and 500 yards of their trenches. He subsequently found and cut 11 of the enemy's mine leads situated about 20 yards apart. He was commissioned a Second Lieutenant in the Special Reserve, The Royal Welch Fusiliers, 26 August 1915.
On 16 March 1917 he was seconded on probation with the Indian Army and was attached to the 4th battalion 3rd Queen Alexandra's Own Gurkha Rifles, with seniority as a Second Lieutenant of 26 May 1916. He was promoted Lieutenant 26 May 1917. He was admitted to the Indian Army on 6 May 1918, promoted captain on 26 May 1920 and retired from the Indian Army on 5 November 1922.