In December 1899, Professor Caesar Boeck (1845-1917) in Kristiania (now Oslo) published his pioneering article on "Multiple benign sarkoid of the skin". At the time, Boeck's sarcoid was a dermatological curiosity, but in his latest work in 1916, Boeck recognised the generalised character of the disease. Today, 100 years later, sarcoidosis is still an enigmatic disease. Caesar Boeck was a hard-working clinician and histologist, the founder of modern dermatovenerology in Norway. This article gives an account of Caesar Boeck's family background, his scientific career and his personality.