Regio Patalis

Regio Patalis is Latin for “the region of Patala”, that is the region around the ancient city of Patala at the mouth of the Indus River in Sindh, Pakistan. The historians of Alexander the Great state that the Indus parted into two branches at the city of Patala before reaching the sea, and the island thus formed was called Patalene, the district of Patala. Alexander constructed a harbour at Patala.^[1][2]

While the Patala was well known to mariners and traders of the Ancient Mediterranean, by the European Middle Ages, mapmakers no longer knew its location. Regio Patalis appeared on late 15th and early 16th century maps and globes in a variety of increasingly erroneous locations, further and further east and south of India. It even appeared on some maps as a promontory of Terra Australis.