Two historians who lost a plagiarism case against The Da Vinci Code author Dan Brown launched an appeal to have the verdict overturned. Michael Baigent and Richard Leigh, who wrote The Holy Blood and the Holy Grail, which they say Brown copied, were at London’s High Court to hear the opening of the appeal. Their lawyer, Jonathan Rayner James, will argue that the original judge was wrong to dismiss the idea of a “central theme” in the historians’ research, which he says was used extensively in six chapters of The Da Vinci Code. “The ... judge ‘rejected’ the central theme because, inter alia, it was not the substantial part of ‘HBHG’ (The Holy Blood and the Holy Grail)”, he said in a printed summary of his argument to be presented in court. “This approach is incorrect; it does not have to be the substantial part of ‘HBHG.” “Was there enough of an expenditure of skill and labor to warrant copyright protection? The appellants submit that there was.” Brown, who was called as a witness during the original case last year, is not expected to be present for the appeal. Judge Peter Smith ruled in April that the central themes were too general or abstract to be protected by copyright.