In August 1950, Jacqueline Lee Bouvier visited Dublin and was shown around the city by a family friend, Fr Joseph Leonard.
He secured an invitation for her to visit Government Buildings and introduced her to his friend, Taoiseach John A Costello.
After the visit, Jackie began a life-long correspondence with Fr Leonard. But she also developed a close bond with Mr Costello and his family and when she married JFK introduced her husband to the Costello family.
In 1955, when she returned to Dublin with her husband the then Senator John F Kennedy, Mr Costello was absent abroad but asked his son Declan Costello (pictured) and his daughter-in-law Joan to host a dinner for the Kennedys on his behalf.
In 1956, John A Costello’s wife Ida died and Jackie wrote to the family to express her condolences.
Jackie did not travel to Ireland with her husband when he visited Ireland in June 1963.
President Kennedy met both John A Costello and Declan Costello at a reception in Áras an Uachtaráin.
In June 1967, Jackie visited Ireland for a month-long private holiday with her children.
She stayed in Woodstown House, Co Waterford.
But she interrupted the holiday for an overnight trip to Dublin to visit president Eamon de Valera at Áras an Uachtaráin and to attend a reception hosted by taoiseach Jack Lynch at Dublin Castle.
Mr Costello was among the guests and afterwards Jackie wrote to him to say “it was such a joy to see you again” and asked him to “please give my love” to Declan (the Taoiseach’s son) and his wife Joan.
John A Costello was the Fine Gael taoiseach (in coalition governments) from 1948 -1951 and 1954-1957.
He died in 1976.
He is best remembered for having announced, during a visit to Canada in 1948, that Ireland was to leave the British Commonwealth and become a republic.
His archives, including his correspondence with Jackie Kennedy, have been donated to UCD.
His son Declan Costello was a Fine Gael TD, later Attorney General, and subsequently a judge in the High Court.
He is best-known for his 1960s policy paper for Fine Gael, titled Towards a Just Society.
He died in 2011.
His correspondence with Jackie Kennedy has not come into the public domain.
Timeline: What’s happening to the Jackie Kennedy letters?
May 13th, 2014: Sheppard's Irish Auction House announced the sale of an archive of previously unseen letters written by Jackie Kennedy – before and after she became US First Lady – to Irish priest Fr Joseph Leonard between 1950 and 1964. Extracts from the letters were published, for the first time, in The Irish Times.
May 14th: All Hallows College in Dublin announced that it was the vendor and had "released the collection for sale" saying that "the college does not have the resources or facilities to properly curate the letters, thereby running the risk of damage and deterioration".
May 21st: All Hallows announced that the letters were “being withdrawn from auction at the direction of All Hallows College and the Vincentian Fathers. Representatives of All Hallows College and the Vincentians Fathers are now exploring with members of Mrs Kennedy’s family how best to preserve and curate this archive for the future”.
Sheppard’s auctioneers handed over the letters to a representatives of All Hallows and the Vincentian Order.
May 23rd: All Hallows issued a statement “It is with huge regret and deep sadness that All Hallows College today announces its intention to wind down the college.”
May 26th: It was reported All Hallows had reported to the gardaí that some rare books and prints were missing from its library. The college said it was not aware of books inscribed by Jackie Kennedy in the library and had “no reason to suspect [their] misappropriation”.
May 26th: The Irish Times asked the Vincentian Order if it could confirm that the order was the owner of the Jackie Kennedy letters to Fr Leonard and what it planned to do with the letters. The questions were directed to a PR company which replied: "The Vincentians have nothing to add to the statement issued on this matter on 21st May, at this time."