Passage: Constantine III (Greek: Κωνσταντῖνος Γ΄; Latin: Heraclius Novus Constantinus Augustus; 3 May 612 – 20 April or 24/26 May 641) was Byzantine emperor for four months in 641, making him the shortest reigning Byzantine emperor. He was the eldest son of the Byzantine Emperor Heraclius and his first wife Eudokia.

Question: Of all the emperor's who had the shortest time as leader?
Constantine III