He had served for almost two decades as Taoiseach and was in 1973 nearing the end of a second seven-year term as President.

But as he prepared to vacate Aras an Uachtarain, de Valera was . . . according to his doctor . . . a worried man. Bryan Alton was so concerned about his patient that he wrote to Taoiseach Jack Lynch. He noted in the correspondence that the founding father of Fianna Fail "is tending to develop a depression.

The main basis for the matter appears to be financial." Alton explained that de Valera was worried that his pension would be "very small and inadequate.

Many elderly people get depressed and feel they are going to end their days in poverty. On the other hand, Mrs de Valera is now a complete invalid and the President has the worry that she will need constant care. His fears may be totally unfounded but he speaks of them very rationally and convincingly." This remarkable insight into the mind of one of the towering figures in this state's history is contained in a document in the National Archives first released in 2003. It is discussed by Dermot Ferriter, in his major reassessment of de Valera, in the context of the apparent gulf in standards between the state's first generation of political leaders and their successors.

The pension story is just one of several new insights into who was Eamon de Valera, and just what was his contribution, as teased out by Ferriter in a new accessible and challenging study.

Indeed, Judging Dev is a resounding success for both the author and his publisher, the Royal Irish Academy. The book is wonderfully produced with its text inter-spread by photographs and illustrations, many of which will be new to even the strongest readers of Irish history.

In one example, a letter from the White House dated 30 June 1972 is reproduced, in which Richard Nixon writes that "the introduction of two men [Dev to Roanld Reagan] whom I deeply admire is a source of great pleasure for me. I ask you to receive Governor Ronald Reagan as my personal representative and friend . . . and as a friend of Ireland." In another archive gem a transcript of an informal conversation between the British Ambassador to Ireland in February 1967 and de Valera has the Irish politician observing that "soccer was the game of the British Army" while "for my part I have always preferred Rugby".

There are hours of reading in the reproduced archive material while the huge selection of photographs are to be marvelled at, and that is before one gets to Ferriter's own text.

The book is not so much a judgement of de Valera, rather a deconstruction of the man and his politics as previously dissected in other publications.

Ferriter takes all the pieces of de Valera's career, re-examines conclusions already reached, and then challenges them as he puts the pieces back together again. It is a fascinating work which, to the author's enormous credit and skill, will appeal to a wide readership. The opening chapter illustrates the diverse views already in the public domain. In the 1975 tributes marking de Valera's death, Pope Paul VI acknowledged the passing of "a true statesman of Europe".

Others had a less benign view.

Tim Pat Coogan, for one, said de Valera did "little that was useful and much that was harmful".

Naturally, the comparison with Michael Collins features. For over a decade now Collins has been the Irish Independence era figure in vogue. His reputation has wooed not just film-makers but also academics. In the simplistic "good cop, bad cop" version of Irish history de Valera has seemed a lesser figure. But as Ferriter notes Collins's premature death diminishes the scale of the work undertaken by de Valera and others in later years. And, as the author correctly concludes, there has been an erroneous and continuing tendency to judge de Valera in the context of the early 1920s rather than looking at his career as a whole."

Across 16 chapters, Ferriter provides not quite a biographical study of his subject but rather separate essays on different aspects of de Valera's long career.

The text follows a chronological time span as the author attempts to work out where our judgement on de Valera should rest today.

He wants his readers to think afresh and dispense with ingrained stereotypes. With access to recently released state papers, and also to de Valera's own private papers, Ferriter's work has an edge over previous studies. On his opening page he sets out his stall by describing de Valera as "the most polarising and significant politician of 20th century Ireland". And that is where this book succeeds.

Ferriter, in general, eschews the hagiography or defamation of previous publications assessing de Valera. "It is time, while acknowledging his mistakes and misjudgements, to reconsider the positive aspects of the de Valera legacy, and to be more broadminded when judging Dev, " the author asserts.

But while striving for a middle ground, the author's fondness for de Valera comes through, and never more so in the story of de Valera's money worries in his final months as President.

Having been alerted to these concerns by the outgoing President's doctor, Jack Lynch visited de Valera the next day and some time later the government recommended increasing the president's salary from �5,000 to �11,000.

Ferriter uses the anecdote to make reference to the current standing of politicians in economic boom time Ireland. "In looking at these documents, there seems something appropriate about the President of a republic being worried about the same issues that would affect so many of its citizens. It is also a reminder of how debased Irish politics has become over the years through its associations with personal enrichment."

But Ferriter does not make any linkage between de Valera's pension worries and an earlier discussion in Judging Dev about his financial interests in the Irish Press newspaper group. Bertie Ahern . . . who launches Ferriter's book in Dublin today . . . may consider himself unfortunate when he considers the controversy which marked de Valera's final period as Taoiseach. In the Dail in 1958 Noel Browne raised the issue of the appropriateness of de Valera's control over the Irish Press newspaper titles. Browne argued that the highly profitable newspaper group had become the political plaything and enormous financial asset of the de Valera family".

Browne questioned the appropriateness of de Valera acting as controlling director and major shareholder in the Irish Press while head of government.

De Valera's own response . . . as summarised by the author . . . was that his position was merely "a fiduciary one", that he had made no money from the newspaper and that the profits had been used to grow the publication.

"But he failed to adequately answer what was a legitimate query, " Ferriter concludes. De Valera's exit from national politics to seek election as president knocked the controversy off the news agenda.

Ahern, with his own conflicts of interest, may rue the fact that he operates today with 24/7 news and a permanent questioning of political motivations. De Valera got off lightly in 1957 and perhaps he does so too today. But then that is the value of Judging Dev . . .

there is no singular judgement in a career that includes controversies over the Treaty of Independence, the Emergency and the economic stagnation of the 1950s. Ferriter . . . who is emerging as the leading historian of his generation . . . has not offered the final say on de Valera, rather he was re-opened the debate about a politician who still casts a long shadow over Irish society. "A unique politician, and a noble one, " the author concludes. It is a good place to renew the debate.