Geoffrey Robertson, the author of The Tyrannicide Brief, enjoys the same high public profile as those old lags who constitute the élite of Australian expatriates in London: Clive James, Germaine Greer, and Barry Humphries. In his case it is as a leading international human rights lawyer, the author of Crimes against Humanity (1999) and The Justice Game (1998), and host of the popular television series Hypotheticals.

At Sydney University, Robertson studied history as well as law. This provides the best explanation of the meticulous research that went into this book, in which the ‘notes on sources’ are as interesting to read as the elegantly written narrative. In 1999 Robertson had a debate in London with Justice Michael Kirby to mark the 350th anniversary of the trial and execution of Charles I. Was it a fair trial? According to Kirby, a monarchist, probably not; according to the republican Robertson, ‘yes’ in the context of legal standards at that time. This is a distant point and very much a lawyer’s one, but, in researching it, Robertson became fascinated by the significance of the events that took place between 1640 and 1660. These included the civil wars, the execution of Charles I, Cromwell’s Protectorate and the restoration of the monarchy in the person of Charles II.