Évariste Galois
To appear on a commemorative stamp is surely the greatest stamp of fame. Évariste Galois -- 'Révolutionnaire et Géomètre', as the French stamp says -- was one of the most unusual and enigmatic mathematicians in history. He died when he was just 20 years old, in dramatic circumstances, but during his brief span he created mathematics which, in the decades after his death, would go on to revolutionise all aspects of the discipline.