Before the discovery of penicillin, syphilis was a widespread, damaging, potentially lethal disease. Sexually transmitted, of course. To the left is a medical illustration of syphilis probably by Albrecht Durer.
In Italy and Germany, syphilis was called "the French disease."
The French called it "the Italian disease."
The English called it "the French pox."
The Dutch called it "the Spanish disease."
The Russians called it "the Polish disease."
The Polish called it "the Russian disease."
The Turks called it "the Christian disease."
Persians called it "the Turkish disease."
The Portugese called it "the Castillian disease."
The Tahitians called it "the British disease."
The Japanese called it either "the Portugese or Chinese disease".
Famous people thought to have had syphilis? Henry VII seems to make most lists, but he doesn't appear on wikipedia's list, which appears to be fairly well-documented:
Charles VIII of France
Hernando Cortez of Spain
Ivan the Terrible
Note that "insanity" is part of the tertiary stage.
Guy de Maupassant
A June 2004 article in the European Journal of Neurology hypothesized that Lenin died of neurosyphilis.
Here is a photograph of a Mobius strip
Photograph of Mobius strip by David Benbennick, wikimedia commons.