Are the Dieppe maps evidence that Europeans discovered Australasia years before the Dutch voyages of the seventeenth century? If so, by whom was it done and when? The main obstacle to a definitive explanation is that there is no known log or chart of a sixteenth century voyage to account for the maps. In them, the austral landmass labelled Java La Grande is a huge extension southwards of the island of Java. How did this inflation come about? The Dieppe maps can at best be the imperfect record of an otherwise undocumented voyage. They could also be a complete fabrication. There is however an intermediate possibility, namely that they are an attempt to interpret a documented but spurious voyage...