The history of syphilis is complex and has left its mark throughout medicine. The origin of syphilis is an important historical and scientific issue in the history of medicine. The Columbian hypothesis which assumes that syphilis originated in the New World ('America') and that Columbus and his crew imported the disease after his voyages of discovery in 1493 to the Old World ('Europe') is the most accepted theory. Misinterpretations of unethical experiments into the causes of syphilis and gonorrhoea from the 17th century to the early decades of the 19th century led to nosological misconceptions. In the late 19th century and 20th century came the great breakthroughs in the fields of microbiology, diagnosis and therapy.