It's a well known fact that the word 'diagonal' comes from the discoverer of such eccentric lines, the famed Greek mathematician Diagon. Less well known, of course, is that Diagon's given name was actually Lysis. Lysis, a Cretan native who lived during the 8th century BCE, only became known as Diagon when, upon his death, he was found to have expired due to an unfortunate combination of diarrhoea and gonorrhea.