President Michael D Higgins, outgoing British Prime Minister David Cameron and French President François Hollande put their Brexit woes behind them to remember a far greater European conflict yesterday.
he heads of state joined government representatives and royalty to lay a wreath marking 100 years since the Battle of the Somme in Northern France.
The battle, which is regarded as the bloodiest of World War I, saw more than one million people killed or injured over a five-month period. In the first day of the battle there were 60,000 casualties who had been fighting for the British Army.
Among those injured or killed during the battle were thousands of Irish troops who served with the British Army.
Some 10,000 guests were in attendance at the ceremony. Current Irish troops serving in the British Army, in battalions such as the Royal Irish Rangers, were there to pay their respects at the Thiepval Memorial in Picardy.
Also in attendance were the Prince of Wales and the Duchess of Cornwall and the Duke and Duchess of Cambridge, William and Catherine, as well as Irish representatives from the country's four main churches.
Catholic Archbishop Eamon Martin, Church of Ireland Archbishop Richard Clarke, President of the Methodist Church in Ireland Rev Bill Mullally and Moderator of the Presbyterian Church Dr Frank Sellar were all in attendance. The group released a joint statement against the backdrop of recent hate crimes and terrorist attacks.
"Let us put our faith into action - love our neighbours, reach out to the stranger, care for the vulnerable, build community and be agents for peace, forgiveness and reconciliation," the statement read.
Writing in the programme for the memorial, Prince Charles said they "return to the battlefield in a spirit of reconciliation and respect".
"We honour the men who served from across Britain and Ireland, the Commonwealth and from France," he said.
There were memorials held closer to home, too.
In Dublin, a flag marching ceremony, which included a lone piper and a minute's silence, was held at the National War Memorial Gardens, Islandbridge.