The hands of history
The peace process can be recorded in handshakes - the universal sign of friendship between the Prince of Wales and Sinn Fein leader Gerry Adams is just the latest "historic" gesture.
It seems that only one remains outstanding - between First Minister Peter Robinson and either Mr Adams or Martin McGuinness of Sinn Fein.
Here are some of the big handshakes that have dotted the peace process since the IRA announced its ceasefire.
1994: Mr Adams shakes hands with SDLP leader John Hume along with Taoiseach Albert Reynolds outside the Dail.
1995: Mr Adams shakes hands with US President Bill Clinton at a Washington St Patrick's Day reception.
2007: Mr Adams shakes hands with Chief Constable Sir Hugh Orde in west Belfast.
2011: Presbyterian minister Rev David Armstrong recreates the handshake with Catholic priest Father Kevin Mullan years after the friendship between them resulted in his receiving loyalist death threats and leaving Northern Ireland.
2012: The Queen and Martin McGuinness mark a milestone in Anglo-Irish relations by shaking hands during the monarch's visit to Northern Ireland.