Labour's Hilary Benn remembered his great uncle Oliver Williams Benn before turning to George Edwin Ellison, the last British solider to be killed in action during the conflict.
The Leeds Central MP was visibly emotional as he spoken in a Commons debate to mark the centenary of the Armistice.
He said: "Oliver was little spoken of in our family when I was growing up, I suspect because the pain of his loss was still too raw despite the passing of the years.
"What we do know about him is thanks to my son James, who wrote a book about his life."
MPs heard Oliver Williams Benn, 38, was commissioned into the Somerset Light Infantry and arrived in Gallipoli on May 26 1915 but was posted missing 10 days later.
Mr Benn said: "The family desperately searched for news in hope that he had been captured.
"His mother wrote regularly to him but gradually the hope faded and at the end of the war, all her letters were returned unopened."
Mr Benn recalled recently tracing his great uncle's journey from the beach to the place where he died, noting the trench where he was last seen is now a field of sunflowers.
"As we stood there in the burning midday sun, my son James read from Oliver's last letter to his mother - in which he wrote 'Goodbye mother darling, please don't worry, all my best love, your very happy boy'."
Mr Benn said his relative's body was never found and is one of more than 20,000 British and Commonwealth soldiers whose names are on the Helles Memorial.
The Commons heard Mr Ellison returned to Mons and was killed by a sniper while scouting the woods on November 11, 1918.
Mr Benn said: "A goodnight kiss, in the slang.
"It was around 9.30 in the morning, an hour-and-a-half before the Armistice. George Ellison was 40 years old."
He added Mr Ellison's grave is a few footsteps from the resting place of the first British soldier to die in action on the Western Front, 17-year-old John Parr.
Mr Benn added: "The first and the last and in between them in time, if not in place, lie the millions who gave their lives in the war that was meant to end all wars, but did not."
He concluded by reading a poem by Philip Parker entitled Goodnight Kiss, which remembers Mr Parr and Mr Ellison.