Irish President Michael D Higgins and his wife Sabina represented Ireland at the First World War centenary ceremony in Belgium yesterday, marking a further normalisation of relations between the UK and the Republic.
President Higgins said the First World War was a horrific event in human history and has to be regarded as such.
The area where yesterday's ceremony was held, is home to the graves where some of the first army casualties of the war – including a number of Irishmen – are buried.
"I think the significance of the heads of state coming together on the anniversary of World War One is an opportunity to recognise the catastrophe the war was," he said.
He said the anniversary also provided an opportunity to ask the question how countries could drift into war and how it could expand to the point at which it consumed a generation that had such promise.
The President said it was wrong of Irish society at the time not to recognise the suffering of those Irish people who fought in the war.
He said that perhaps they suffered in silence because they came home in the shadow of the execution of leaders of the 1916 Rising.
He said the Irish were scattered across this experience of war and they must understand their role in it. A total of 49,400 Irish died in the conflict.
The event was also attended by the leaders of France, Germany and Austria. Over a dozen heads of state from across the globe attended.
German President Joachim Gauck described his country's invasion of neutral Belgium as completely unjustifiable, as were the atrocities committed against civilians and Belgium's cultural heritage.
French President Francoise Hollande, pointedly remarked that Europe could not remain neutral in the face of conflicts in Ukraine and in the Middle East.
"We can't just be guardians of peace and remember. We can't remain neutral on Iraq, Syria, Gaza," he said.
President Higgins also attended a ceremony at a joint Allied-German cemetery in nearby Mons, where the first Irish fatalities occurred in August 1914.