As I was in Texas, he apparently did not realise I was Irish.

He noted that President Éamon de Valera’s son Vivion, was his boss, and he underlined Vivion’s name in the letterhead, adding he was sure I would write with an historian’s dispassion. It seemed like a patent hint that I had better be favourable.

My first book, Irish Neutrality and the USA, was considered highly favourable to de Valera, so when I was invited to address a Tralee group in Dublin about the book, I sought to balance things by concentrating on an aspect that reviewers had ignored — the impact of de Valera’s cynical exploitation of the partition issue.

Maurice Moynihan — a Tralee man who had served as secretary of the taoiseach’s department during de Valera’s tenure — took exception to my comments. He spoke for over five minutes with his wife tugging at his jacket.

Afterwards he said to me that he hoped I did not take offence, so I used the opportunity to ask him for an interview. Dr Moynihan was quite helpful any time I approached him afterwards. Possibly he did not realise on the night that my overall views in the book were favourable of de Valera’s handling of neutrality.

Gill & Macmillan asked me to write a short biography of de Valera for the Gill’s Irish Lives series. I came across some startling information about his surrender in 1916. Although he is frequently described as the last commandant to surrender during the Easter Rebellion, that distinction really belonged to Tomas Ashe.

While covering Áras an Uachtaráin, during the 1966 commemorations of the 1916 Rising, Dick Walsh of The Irish Times told me that some of the men in Boland’s Mills in 1916 had informed him that de Valera had abandoned them and surrendered to the British on his own. When he received the order to surrender, de Valera sent the messenger to get the order countersigned by Thomas MacDonagh. It soon became obvious, however, that the surrender order was valid, because the shooting died out around the city.

De Valera therefore, decided to hand over a British solider that his men had been holding prisoner. He brought him to Sir Patrick Dunn’s Hospital and handed him over to the British garrison there, and also surrendered himself.

Walsh indicated that The Irish Times was not interested in that story in 1966. I later learned this was probably because the editor, Douglas Gageby — who had got his start in The Irish Press — was reluctant to publish anything critical of de Valera.

After publishing de Valera’s biography, I submitted a series of articles to The Irish Times that were critical of de Valera’s handling of the partition question. The late Paul Tansey, the assistant editor, accepted the articles, but the week before they were due to run, he called me to say that I should talk to Gageby, whom I duly met in his office.

Gageby quizzed me about my favourable views on de Valera’s handling of international affairs. Ironically, my only reservation was the manner in which he had essentially ensured that Seán Lester, the last secretary general of the League of Nations, retired into oblivion after the Second World War. He was the one Irish person with the stature to vie with de Valera on the international scene.

By the late 1970s, Lester was almost totally forgotten. Gageby told me Lester was much better off in retirement, because he enjoyed a quiet life of fishing in his final years. Much to my surprise, he added that Lester had been his father-in-law.

Gageby indicated that he would be interested in series of extracts from my forthcoming book In de Valera’s Finest Hour, but would not publish the articles on partition.

I later combined those articles to write a chapter on de Valera and partition for the book, De Valera and His Times. The Irish Times asked me to review that book. I concluded that while the book was very good on de Valera’s positive contributions to Irish life, some of the contributors went over the top with their praise.

Former taoiseach Jack Lynch, who launched the book, quoted extensively from the review, but he went on to say that one could not praise de Valera too highly. On being told that I was present, Lynch asked to talk to me, and expressed the hope I did not take offence at his comments. On the contrary, I was flattered that he had quoted from the review.

Lynch was obviously a great admirer of de Valera. He mentioned that many people did not realise he had a great sense of humour.

While he could not recall any instances of de Valera telling jokes, he said the Long Fellow would laugh at the jokes told by others, especially when they poked fun at himself. All too often those who are great at poking fun at others, cannot take it themselves. But de Valera had a disarming ability to laugh at himself.

In Jan 1922, he had talked about his desire to retire from public life. He did finally retire, more than half a century later, on Jun 24, 1973. He had the last laugh.