President Mary McAleese and Northern Ireland First Minister Ian Paisley have attended a function at the Somme Commemoration Centre in Newtownards, Co Down.
President McAleese was greeted on arrival by the First Minister, who shook hands with her.
It is the first time they shared a platform since Dr Paisley entered a power-sharing administration in May.
Potentially it could be another significant event in the new politics of Ireland.
Mr Paisley is a long-standing supporter of the Somme Heritage Centre at Newtownards.
Nine years ago, President McAleese inaugurated a Peace Tower in Belgium, dedicated to all the Irish who fought and died in the First World War.
Earlier, the President met with the Newtownards Community Forum at the Town Hall.
The group, which includes representatives from local community groups, the PSNI, the Youth Service, representatives of the loyalist community and members of the local clergy, works together to improve community life in the area.
The President also visited Regent House School, one of the largest grammar schools in Northern Ireland.
The President is due at Queen's University, Belfast tonight where she will attend the 30th anniversary dinner of the Institute of Professional Legal Studies, the body responsible for the vocational training of trainee barristers and solicitors.
President McAleese was Director of the Institute from 1987 until her election in 1997.
