Notes by Private Charles Snelling, who died fighting in the Battle of Passchendaele near Ypres in 1917, were addressed to his wife Alice and daughters.
Writing to Alice before the battle began, he said: "When this little picnic is finished we will have the old times over again making up for these months of parting."
The letters, along with a photograph of Alice (pictured below) which Charlies carried with him, were found by a corporal in the Soldiers Christian Association, months after he died in action.
They were discovered with a note, which said: "I am very sorry to say I could not find the owner of the photos. I cannot say if he has been wounded or killed".
Charles, who was killed in an attack on Glencorse Wood during the Battle of Passchendaele on August 15th, sent a final postcard to his wife the day before, which said: "I am quite well. Letter follows at first opportunity".
The notes by Charles Snelling are among several letters by First World War soldiers which are being made public to mark centenary commemorations of the bloody clash.
A ballot for tickets to attend the official commemorations of Passchendaele - the Third Battle of Ypres - in Belgium closes next Friday.
Visit passchendaele100.org for more details.