David Irving v Penguin Books and Deborah Lipstadt is a case in English law against American historian Deborah Lipstadt and her British publisher Penguin Books, filed in the High Court of Justice by the British author David Irving in 1996, asserting that Lipstadt had libelled him in her 1993 book Denying the Holocaust. The court ruled that Irving's claim of libel relating to Holocaust denial was not valid under English defamation law because Lipstadt's claim that he had deliberately distorted evidence had been shown to be substantially true. English libel law puts the burden of proof on the defence, meaning that it was up to Lipstadt and her publisher to prove that her claims of Irving's deliberate misrepresentation of evidence to conform to his ideological viewpoints were substantially true. Lipstadt hired British lawyer Anthony Julius while Penguin hired libel experts Kevin Bays and Mark Bateman of media law firm Davenport Lyons. Richard J. Evans, an established historian, was hired by the defence to serve as an expert witness. Evans spent two years examining Irving's work, and presented evidence of Irving's misrepresentations, including evidence that Irving had knowingly used forged documents as source material. Of utmost importance was the role played by another expert witness for the defence, the Holocaust historian Christopher Browning. Upon mutual agreement, the case was argued as a bench trial before Mr. Justice Gray, who produced a written judgment 349 pages long in favour of the defendants, in which he detailed Irving's systematic distortion of the historical record of the Holocaust and Hitler's role therein. In 1993, Free Press published Professor Deborah Lipstadt's book Denying the Holocaust: the Growing Assault on Truth and Memory. In it she described and condemned the phenomenon of Holocaust denial and referred to David Irving as a prominent Holocaust denier. One of the passages Irving later objected to was: Irving is one of the most dangerous spokespersons for Holocaust denial.