Historic event was 21 years in making
A succession of men played key diplomatic roles but it was two women whose patient work really secured the visit of Queen Elizabeth.
Mary Robinson and Mary McAleese, symbols of a new Ireland, forged a fresh relationship for this young state with an ancient British monarchy.
In the 1990s, an Irish President and British monarch, both women, sitting drinking tea together, offered hope when the rest of the world saw the relationship between their nations predicated by violence. From her election in 1990, Mary Robinson used her role as head of state in Dublin to pursue new channels of communications with her equivalent in London.
Protocol frowns on heads of government doing business with heads of state so Mrs Robinson set in train a diplomatic slow coach that took 21 years to arrive.
In 1993, a year before the first IRA ceasefire, Mrs Robinson took a bold step by shaking hands with Gerry Adams -- an MP and believed to be a member of the IRA Army Council.
Unionist anger over the then President's acknowledgement of Mr Adams's role in secret peace talks was matched by the furore from Republicans when she travelled to London to meet Queen Elizabeth.
And when Mrs McAleese was pro-chancellor of Queens University in Belfast she received a curious but discreet message: Queen Elizabeth wanted to meet her, to hear first-hand the views of a northern Irish nationalist.
So Mary McAleese was no stranger when she later visited Buckingham Palace. She and the queen were reported to have formed something beyond "a good working relationship".
Mrs McAleese wanted the first visit to this proud, independent young state by a British monarch to happen on her watch, which ends in October.