Former president Mary McAleese has said Prince Philip and Queen Elizabeth felt a "duty" to bring about reconciliation between Britain and Ireland.
Belfast-born Mrs McAleese was president during the historic 2011 visit of Queen Elizabeth and the Duke of Edinburgh, the first by a British monarch to the country in 100 years.
The Duke died on Friday at the age of 99.
Speaking on The Andrew Marr Show on the BBC, Mrs McAleese said: "I was lucky to have an insight into the desire of both ... the Queen and Prince Philip for precisely that reconciliation.
"They both gave me to understand that they really wanted to visit Ireland, they wanted it to be part of a process of reconciliation.
"They saw themselves as people who had a duty to do whatever they could, by way of bringing about that reconciliation between neighbours.
"And so when they came in 2011, it was at the end of a long process.
"We had the Good Friday Agreement and that was a long, long, political journey to get to the point where we could offer that visit to Her Majesty the Queen.
"And of course, when they both came they were greeted very warmly. Why?
"Because people recognised in them, in every gesture and everything they did, in the speech that the Queen gave, they recognised people who weren't just there as state visitors, but in some ways we're on a kind of pilgrimage of reconciliation."
Mrs McAleese said Prince Philip travelled to Ireland in 2011 "on a mission to heal history".
She said: "You can understand that security was very high, concerns were high.
"So he was there, as she has described in the past as her rock, but he was also there as a character in his own right.
"A man who had come on a mission, as she had come, both of them had come on this mission in their own right to try and heal history, to ensure that for the future these two neighbouring islands would be characterised by good neighbourliness.
"He wasn't just there as her company, if you like, her inevitable company, he was also there making a statement."
She said that although the pair subsequently met, Philip would have been willing to meet Martin McGuinness on that visit, had Sinn Féin not objected.
Mrs McAleese added: "He was willing even then to meet people who have been so closely associated with the murder of a man who had meant so much to him, Lord Mountbatten."