They arrived in a white minibus, surrounded by police motorcycle outriders as they swept through the gates of what was once the seat of British power in Ireland. It was, an Irish minister said, 'a historic day by any standards'.
But James Molyneaux, leader of the Ulster Unionist party, had time for neither handshakes nor photo calls as he hurried tight-lipped into the building; and this most modest of politicians will not have liked the sirens and flashing lights which accompanied his delegation's departure last night.
Given Mr Molyneaux's distaste for the dramatic, everyone missed the Rev Ian Paisley and his renowned flair for political theatre. But Mr Paisley had said he would only go south if Dublin offered him some concession on the Irish constitution, and this was not forthcoming.
Ireland is a small place. Had Mr Paisley's deputy Peter Robinson made the trip, and wandered into the castle canteen, he would have run into Justice Liam Hamilton. A few years back Justice Hamilton was the judge who fined Mr Robinson thousands of pounds for taking part in a nocturnal incursion across the border into the south. Times have changed, however, and yesterday the Irish police were escorting Unionists rather than arresting them.
The absence of Mr Paisley and Mr Robinson is one sign of the difficulties the talks are experiencing. Having failed to reach agreement on how Northern Ireland's internal administration should be handled, the participants have now moved on to the question of future north-south relations.
Behind the closed doors, the Unionists will have argued for changes to the Irish constitution, while Nationalists sought to establish what might be on offer in exchange for such a move.
History was all around them as they talked. They lunched in St Patrick's Hall beneath an extravagant 18th-century depiction of Henry II receiving the surrender of Irish chieftains in 1171.
A great deal of water has flowed under the bridge since then. Yet, as the necessity for continuing talks demonstrates, the Irish question still awaits final settlement. It will take some time to show whether the talks will have substance as well as symbolism.Reuse content