Thomas and Edmund were the sons of John and Margaret O’Brien. They lived and worked as Farmers at Graman, north of Inverell NSW. Both men enlisted at Inverell on 29 June 1916 and became members of the 29th Battalion 11th Reinforcement. Thomas was thirty six and Edmund twenty six. They sailed from Australia on HMAT A19 Afric in November 1916 and arrived in England at the beginning of January 1917.
After three months Thomas was sent to France. By August he was suffering from Trench Fever and returned to England for treatment at Bethnel Green Hospital. He went back to France In November. The following year he was promoted to Lance Corporal in October and transferred to the 32nd Battalion. Thomas returned home in June 1919. He married in 1920 and lived in the Inverell district until moving to Warwick, Queensland where he died in 1968.
Thomas has his name recorded on the Inverell, Bonshaw and Graman Honor Rolls.
Edmund was also sent to France at the same time as his brother and four months later was wounded in action. He was transferred to England for treatment of a gunshot wound to his arm. After attending a Signals School he returned to France in April 1918 and was transferred to the 21st Battalion. Private Edmund O’Brien was killed in action on 30 September 1918 at Navroy, France. He was buried at Bellicourt British Cemetery, France.