13. A simple re-alignment of the map places everything in correct position.

The Vallard Atlas map describes a place called "Terra Java" which bears strong similarities to Australia's coastline - except that, at one point, it juts out at right angles for more than 900 miles.

Note: the French photographers designed maps in the southern hemisphere upside down. For ease of viewing, we have put the map up the correct way, with the images being upside down.

Peter Trickett in Beyond Capricorn provides a straightforward explanation by stating this is because the portolan fragments had not been assembled in the correct way.

 It occurred to Trickett that cartographers in France looking at the Portuguese charts may have completed the Atlas in isolation to the navigators who originally produced them. Putting together the portolan charts, many drawn on animal hides, would be a bit like composing a jigsaw puzzle. Trickett believes that the cartographers wrongly joined two separate charts, causing distortions in the coastline. When corrected, the maps appear to accurately depict Botany Bay and other landmarks.

When Trickett rotated part of one map 90 degrees, he ended up with a picture that fitted Australia's east coast. The original portolan maps would have been drawn on animal hide parchments, usually sheep or goat skin, of limited size. For a coastline the length of eastern Australia, some 3,500 kilometres, there could have been three to four charts.

The Vallard Map positions Illa do Magna north of the actual North Island's geographical location. This misalignment results from the portolan showing an eastern promontory originating from Australia. By reorienting the eastern Australian coastline, the North Island aligns with its actual geographical position. The distance between Cape Howe, southeast Victoria and Cape Egmont, Taranaki is about 2100 kilometres, and from Auckland to Wellington is 600 kilometres, which the Vallard Map accurately reflects.

The likelihood of a sixteenth-century cartographer fabricating the coastlines of eastern Australia and northern New Zealand is minimal, given their close alignment with what we know 500 years later. The detailed depiction and numerous place names suggest that an early voyager must have visited these locations, as such precision and quantity of names are unlikely to be mere products of imagination.

Your next read in the series: 14. How did a small country like Portugal become a major maritime power?