Piri Reis (full name Hacı Ahmed Muhiddin Piri - Hadji Ahmed Muhiddin Piri, Ahmet ibn-i el-Haç Mehmet El Karamani; Reis was a Turkish military rank akin to that of captain) was an Ottoman admiral, geographer and cartographer born between 1465 and 1470 and died in 1554 or 1555.

He is primarily known today for his maps and charts collected in his Kitab-ı Bahriye (Book of Navigation), a book that contains detailed information on navigation, as well as very accurate charts (for its time) describing the important ports and cities of the Mediterranean Sea. He gained fame as a cartographer when a small part of his first world map (prepared in 1513) was discovered in 1929 at the Topkapı Palace in Istanbul. His world map is the oldest known Turkish atlas showing the New World, and one of the oldest maps of America still in existence anywhere (the oldest known map of America that is still in existence is the map drawn by Juan de la Cosa in 1500). Piri Reis' map is centered on the Sahara at the latitude of the Tropic of Cancer.

Graham Hancock (born 2 August 1950 in Edinburgh, Scotland) is a British writer and journalist. Hancock specialises in unconventional theories involving ancient civilizations, stone monuments or megaliths, altered states of consciousness, ancient myths and astronomical/astrological data from the past. One of the main themes running through many of his books is the possible global connection with a "mother culture" from which he believes all ancient historical civilizations sprang.

Born in Edinburgh, Scotland, Hancock's formative years were spent in India, where his father worked as a surgeon. Having returned to the UK, he graduated from Durham University in 1973, receiving a First Class Honours degree in Sociology.

As a journalist, Hancock worked for many British papers, such as The Times, The Sunday Times, The Independent, and The Guardian. He was co-editor of New Internationalist magazine from 1976–1979 and East Africa correspondent of The Economist from 1981-1983.