Alexander Martin Sullivan, Irish lawyer best known as the leading counsel for the defence in the 1916 treason trial of Roger Casement, is born in Dublin on January 14, 1871. He is the last barrister in either Ireland or England to hold the rank of Serjeant-at-Law, hence his nickname The Last Serjeant.
A younger son of A.M. Sullivan and Frances Donovan, Sullivan is educated at Ushaw College, Belvedere College, Trinity College, Dublin and King’s Inns. He is called to the Irish Bar in 1892 and practises on the Munster Circuit.
A moderate constitutional nationalist and supporter of the Irish Parliamentary Party, Sullivan is a prominent campaigner for the recruitment of Irishmen into the British Army during World War I. His opposition to Sinn Féin republicanism and his prominent role in conducting prosecutions on behalf of the Crown during the Irish War of Independence lead to at least one attempt on his life. As a result, he relocates to England in 1921 and establishes a career at the English Bar, having previously been called to the Middle Temple in 1899. He subsequently becomes a Bencher and Treasurer of Middle Temple. By courtesy, he is always referred to as Serjeant Sullivan, even though that rank no longer exists in England.
Sullivan remains a member of the Irish Bar, and returns at least once to appear in the celebrated case of Croker v Croker, where the children of the former leader of Tammany Hall, Richard “Boss” Croker attempt to overturn his will, which leaves his entire estate to their stepmother.
Sullivan is noted as a fearless advocate, who brings to his English practice the robust manners he had learned in the Irish county courts. He does not hesitate to interrupt the judge, and if he feels that he is not receiving a fair hearing, he is quite capable of walking out of Court.
In 1916 Sullivan is retained as lead counsel in the trial of Sir Roger Casement for treason. No English barrister will defend Casement, and Sullivan is persuaded to take the case by George Gavan Duffy, whose wife Margaret is Sullivan’s sister. Despite his rank of Serjeant at law and King’s Counsel at the Irish bar he is only ranked as a junior barrister in England. As the facts relied on by the prosecution are largely undisputed, Sullivan is limited to arguing a technical defence that the Treason Act 1351 only applies to acts committed “within the realm” and not outside it. The Act’s terms had however been expanded by case law over the previous 560 years, and the defence is rejected by the trial judges and by the Court of Criminal Appeal.
Sullivan writes two books: Old Ireland in 1927 and The Last Serjeant in 1952. He retires from legal practice in 1949. He dies on January 9, 1959.