His plans, however, miscarried. Only a handful of Irish prisoners were persuaded to join him, and Casement became convinced that Germany had no intention of risking an expedition to Ireland, without which the imminent Dublin Rising would be hopeless. In April 1916 Casement was arrested on the west coast of Ireland, where he had come ashore from a German submarine, and taken to London to stand trial. At the Old Bailey he was convicted and sentenced to hang. A campaign for his reprieve received distinguished support: Shaw, Chesterton, Yeats, Masefield and Arnold Bennett were among those who put their names to it, and petitions flowed in from around the world, emphasising Casement's exemplary humanitarianism. In his appeal for clemency for his friend, Sir Arthur Conan Doyle wrote that Casement's treasonable acts were brought on by his sufferings in the tropics: "it appears that some allowance may be made ... for his abnormal physical and mental state."
But behind the scenes, another campaign, intended to discredit Casement and ensure that he went to the gallows, was taking place. Among Casement's papers, seized at the time of his arrest, were four diaries recording countless casual homosexual encounters and revealing, in the words of one Home Office official, that Casement had "for years been addicted to the grossest sodomitical practices". F E Smith, for the prosecution, handed the diaries to Casement's defence team, suggesting that they could be used for a plea of insanity. It was a clever ploy. Their publication in open court would have had a sensational effect, alienating sympathy from Casement at home and in America, and preventing him from becoming a martyr for the Irish nationalist cause.
But the defence would not use them. Whitehall then embarked on a well- orchestrated campaign to blacken Case- ment's reputation. Typed extracts from the diaries were circulated to journalists, politicians and the American Ambassador in London. Attempts for a reprieve were halted. Casement went to the scaffold, said the attending priest, "with the dignity of a prince".
Mystery, like some dense fog, swirled around these diaries for too long. Successive governments refused to allow inspection of the originals, and leaders of the new Irish Free state colluded in their suppression, concerned to protect Casement's place in their pantheon of national heroes. Meanwhile, predictably in the absence of any original documents to authenticate, a counter-attack developed. This argued that the diaries were forgeries, concocted by Whitehall propagandists who interpolated salacious passages into the account of Casement's day-to-day activities. The diaries were finally made available to historians in 1959, and to the general public in 1995.
It is a fascinating story, and Roger Sawyer is to be applauded for having presented, for the first time, an accurate text and detailed commentary for just one of the so-called "Black" Diaries, the volume for 1910, the year in which Casement was investigating the ill-treatment of natives in the rubber-producing regions of the Putumayo river. Sawyer is an avowed believer in the authenticity of the diaries, and for comparative purposes he has included an abridged version for the same year of Casement's "White" diary, his public account of events which he used in the writing of his official reports.
The weight of evidence now supports the arguments that the Black Diaries are genuine. They have been examined twice by forensic scientists, in 1959 and in 1993, and on both occasions the conclusions were that they were Casement's work. The 1910 diary provides a representative sample of the descriptions of sexual encounters which have been the source of such contention. There are mostly terse, occasionally more fulsome, accounts of Casement's meetings with rent boys in London or Peru, sometimes with an "X" to indicate that sex had taken place, and including impressions of fancied men, with a compulsive desire to record the size and shape of their genitals. "Saw from my window a splendid type," he writes, "one of my lovely Indians, thick limbs, sturdy with a big one."
There is nothing here that will shock any observer of modern sexual mores, though Sawyer himself, commendably anxious to stress Casement's contribution to the stamping out of slavery, sometimes strikes a nannying note, as when he states that the "disillusioning" sexual material of the diaries has to be "faced up to" if an informed judgement about Casement is to be made. What continues to be interesting about Casement is the way in which he managed so effectively to compartmentalise his life, as brave humanitarian, loyal public servant, as hero of Irish nationalism, and as sexual outlaw.
He may not live up to T E Lawrence's description of him as "a broken archangel", but on the evidence of these diaries the last word on Roger Casement is very far from having been written.