An Australian author named Peter Trickett has discovered a map that pretty well proves Australia was discovered around 1520, which is way before James Cook stumbled upon the place. It is believed that the Portuguese were the first to sight the Australian continent, but there are no records within Portugal itself to substantiate the claim. The source for this claim are the Dieppe Maps, which date between 1542 and 1587, and which were drawn up by a group of French cartographers using a Portuguese source.