Shortly before the Second World War, Alan Turing invented the fundamental logical principles of the modern digital computer. Turing was, however, a misunderstood and relatively isolated figure, who made little attempt to communicate with the main centres of postwar computer development in the US. He generally received at best a minor mention in histories of the computer written in the 20th and early 21st centuries. All that changed in 2012, Turing’s centenary year, and he is now popularly regarded as the founding father of computer science. But an academic backlash has developed. ‘Turing deniers’ seek to show that Turing made no very significant contribution to the development of computers and computing. We examine the arguments of some leading Turing deniers.