While searching through boxes of old family photos at her mother's home in the United Kingdom, Gail Cooper unearthed a long-forgotten family mystery.
The life of her paternal grandfather, Lieutenant Michael Joseph O'Brien, is something she had heard stories about, but the extent of its intrigue has grown in the 30 years since Mrs Cooper uncovered the wooden chest.
Mrs Cooper and her granddaughter Rebecca Bloomfield spoke to The Daily Advertiser via video link from their home in COVID locked down Ruthin, North Wales.
"I'd always known he was a war hero, then when Mum went into care, we cleared the house and found a box of his war medals and photos," Mrs Cooper said.
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Inside the box, Mrs Cooper found her grandfather's military cross and Serbian Gold Star awarded. She wrote to the Australian military and secured detailed records of his service in the United Kingdom, France and surrounding Europe.
They believe he served with the 2nd Machine Gun Battalion in World War One, though much of the family's investigation has been hindered by Michael's common name.
"There was a lot of Michael Joseph O'Briens all over the United Kingdom, Australia and even America," Mrs Cooper said.
"We don't have a death certificate for him because his name is so common. We'd love to find out where he died."
But it's his life following the military that remains a mystery. The family understands that sometime in late 1917 or 1918, he arrived in the United Kingdom where he met a married woman by the name of Mary May Wellman.
They had an affair and she had a child in September 1918. That child, Gordon O'Brien, became Mrs Cooper's father.
Michael's military records show he was discharged in 1919 to stay in the United Kingdom "on compassionate grounds". But his last known whereabouts was in February 1920.
"He [Michael] disappeared when my father was just two, we have no idea where he went," Mrs Cooper said.
"If he did go back to Australia, did he quietly marry and have another family? We'd love to know."
With the historic trail now cold, Mrs Cooper is seeking assistance across the seas.
When he left Australia with the military in 1915, he left behind many connections to Wagga and the Riverina, though he had journeyed extensively as a "commercial traveller" before the War.
Although the family has never been able to find a definitive birth certificate, war records indicate Michael was born in Goulburn in 1893.
When he enlisted in January 1915, he crossed out the name of a John Breen - believed to be his uncle who lived in Junee - as his next-of-kin.
Instead, the young Michael had written his friend Elsie Henry as his preferred next-of-kin. With the address field marked with only 'Wagga Wagga', when it came time for the military to contact Ms Henry in 1918, she could not be found.
"He was obviously a bit of a lad, he got himself in and out of troubles," his granddaughter said.
Letters kept by the Australian military indicate he was known to an Angus Byron Craft (or Croft) who lived in Baylis Street, Wagga.
"He [Angus] said he was looking for Michael and a cousin [Michael John Breen], he said he had a message to pass on," Mrs Cooper said.
Throughout the 1920s and 1930s, a Dennis Breen of Fairlight at Junee Junction wrote to the military inquiring of Michael's whereabouts.
The letters went unanswered as far as Mrs Cooper and her granddaughter, can tell.
"We know at least that he existed," said Ms Bloomfield.
"We don't know much about what he did."
In the hopes of "filling in the blanks for the family", Mrs Cooper and her granddaughter are appealing for anyone in the Riverina who may know of the elusive Elsie Henry, Angus Craft, John Breen, or even the enigmatic Michael O'Brien, to get in touch.
"We don't want anything more than to the solve the family mystery and know a bit more about him [Michael]," Ms Bloomfield said.
If you have any information that could shed further light on the life of Lieutenant Michael Joseph O'Brien, email Daily Advertiser history reporter, Emma Horn:email@example.com.