How wonderful to see those happy, smiling Irish football fans in France for Euro 2016. A hundred years ago, how many similar young lads would be setting off for the killing fields of Flanders, to be slaughtered in their thousands at the terrible Battle of the Somme?
For, at 7.30am on July 1, 1916, the Somme offensive commenced. By lunchtime, there were nearly 60,000 casualties among British and Irish troops - including the devastation of the 36th Ulster Division.
The Ulstermen fought valiantly - yes, they went into battle with their ancestral cry of "No surrender!" - and they breached the German lines, but they were forced to withdraw in the face of counter-attacks. They suffered 5,000 casualties on the first morning. Sir Edward Carson, who had so ardently encouraged the Ulstermen to fight in the 1914-18 war, never recovered, politically or psychologically.
The area around the River Somme is today such a beautiful, peaceful part of eastern France, its poppies still ablaze on the hedgerows; and the small towns of wartime association - Peronne, Albert, Pozieres, La Boisselle - could almost be described as sleepy. But everywhere throughout the countryside you see the military cemeteries with their rows of identical graves: some carry a soldier's name, many bear only the words "A soldier known unto God", the consoling phrase that Rudyard Kipling devised for those unnamed "missing".
Over the past few years, a Yorkshire couple, Pam and Ken Linge, have dedicated themselves to collecting names, photographs and short biographies for their book, The Missing of the Somme. Over the summer and autumn of 1916, some 73,000 men serving with the British army (including Australians and South Africans) were declared missing, and sometimes their remains were never found. Even today, skeleton parts are still churned up in the soil.
There's a fine new museum at the Thiepval Visitor Centre (near to the towns of Albert and Pozieres) with a section dedicated to "the missing" successfully traced by the Linges, with their names and pictures, as well as many of the personal little souvenirs that have come to light: pipes, lighters, diaries, letters from home, prayer books, poetry books, memorabilia. So many young faces - and so many brothers from the same family who died at the Somme, sometimes just a few days or weeks apart.
Among the Irish missing is the renowned Tom Kettle, aged 36, lieutenant with the 9th Battalion of the Royal Dublin Fusiliers. Kettle was a brilliant young lawyer, writer, academic and parliamentarian who was married to Mary Sheehy (sister of Hanna Sheehy-Skeffington). He died "leading his men with great gallantry" in September 1916. In his last letter, sent to his brother, he wrote: "If I live, I mean to spend the rest of my life working for perpetual peace. I have seen war and faced modern artillery, and I know what an outrage it is against simple men." He added that he was "desperately anxious to live". Tom Kettle was a great loss to Ireland.
Another of the Irish missing was William MacCarthy-O'Leary, aged 22, from Coomlagane, Co Cork, of the Royal Munster Fusiliers. He came from a Catholic military family, and was educated by the Jesuits. In his last letter he wrote: "I am going to a show (a battlefield engagement) tonight in which I have rather a poor chance of coming through. God is good, and His will be done. I hope to be spared: but it is a nerve-trying raid." He did not survive the "show".
Some of the other young faces looking out at us include: Thomas McCormick (25), born in Dundalk, who served with the Manchester Regiment, first as a boy bandsman. He became the British Empire Welterweight Boxing Champion in 1914. His mate said that, in battle, he was joking right up to the end. Stanley Thomas Wilkinson (21), from Foynes, Co Limerick, who served with the North Lancashire Regiment and was awarded a posthumous Victoria Cross. David Blakey (26), of the Royal Inniskilling Fusiliers, and Thomas Robinson (20), of the Royal Irish Rifles, along with his brother, William (22), all killed on the Somme's first day. And still so many only "known unto God".
The Somme was to become a byword for the appalling slaughter and destruction of human life that modern industrial warfare came to represent. It was also a turning point in the 1914-1918 war. After 1916, the poets began to write bitterly - not gloriously - about the experience of war.
Yet the memorials at Thiepval - there's a special "Ulster Tower" set aside for the fallen of the 36th division - are moving, peaceful, and redemptive. The French and German losses are equally respectfully marked at the stunning Historical Museum in a mediaeval chateau at nearby Peronne. It's touching to notice that the German soldiers often had some musical instrument with them.
Mournful though the Somme's history is, its remembrance can be healing. Jeffrey Donaldson of the DUP spoke at the Irish Embassy in London last week about how the memory is now part of peace and reconciliation: it is serving to emphasise our "shared history", rather than any sectarian version of it, and Martin McGuinness's tweets honouring the sons of Ulster marching towards the Somme has underlined that remarkable narrative.