Ninety years after men from the 16th Irish and 36th Ulster divisions clambered out of their trenches to face the German army in the battle of Messines Ridge, their sacrifice was marked with wreaths and a pipers' lament.
At a ceremony on Saturday, President Mary McAleese laid a laurel wreath, while Northern Ireland Arts and Culture Minister Edwin Poots laid a wreath of poppies to commemorate the 70,000 Irish dead and wounded during the first World War.
The Irish Ambassador and British ambassador to Belgium also paid tributes to the soldiers from both religious traditions in Ireland who fought side by side in the famous battle.
"We know they came from different traditions which had very different ambitions, and yet on these fields their different traditions were put to one side. They were human beings who had a common cause and, through each other, they worked for that cause and showed to each other a goodness, a graciousness, a kindness, a love, a cherishing of one another," said President McAleese on her third visit to Messines to honour the Irish war dead.
"It is a shared memory and we need shared memories."
Representatives of the Irish Defence Forces and the British army also paid their respects at a ceremony at the Island of Ireland Peace Park in Flanders, Belgium.
"There is a great symbolism here, as the people that built this peace park and fought in the battle were from both north and south of the Border," said Padre Kevin Graham of the Royal Irish Rangers, reflecting on moves toward reconciliation in Northern Ireland. "These events also act as a healing process for people who lost relatives."
For Mable Pearson from Donegal, the event was a personal affair. Her uncle, Andrew Charles Lockhard, was killed aged 22 in the attack at Messines on June 7th, 1917.
"I never met him but I feel like I knew him. My mother talked about him a lot and said he was a really good man," said Ms Pearson, who was wearing miniature replicas of the medals her uncle was awarded.
One of her most treasured possessions is the collection of 80 letters her uncle sent from the front to the family. "I've read all the letters. He never wrote anything about the hardships of the war . . . The strange thing is he only wrote goodbye twice - once in the very first letter he sent and again before the battle," she said.
Mabel's uncle fought with the 36th Ulster Division while Michael Wall, a relative of another participant at the ceremony, Andrew Kavanagh, fought for the 16th Irish. "He was on his way to UCD aged just 19," says Mr Kavanagh. "It was a real tragedy for the family because he was the eldest son. The family had a tough time after that."
The battle for Messines Ridge was a military success for the Allied forces, although they suffered up to 16,000 casualties in the attack.
In Ireland, it is best known for the symbolism of unionists and nationalists fighting together against a common enemy at a time when political divisions were bitterly entrenched at home.
Yet until the opening of the Island of Ireland Peace Park in 1998, the Irish soldiers who lost their lives in the first World War were largely forgotten as the Republic forged its identity.
A decade later, their memory is being further rediscovered.
"These stories were stories kept in shoe boxes in attics. That was a ridiculous place for them, a tragic and shameful place for them. Now they are out and open and cherished, recognised, respected and talked about and loved and admired," said Mrs McAleese.