Seleucus III Soter, called
Seleucus Ceraunus (
Greek: ; ca. 243 BC – 223 BC), was a ruler of the Hellenistic
Seleucid Kingdom, the eldest son of
Seleucus II Callinicus and
Laodice II. His birth name was Alexander and was named after his great uncle the Seleucid official
Alexander. Alexander changed his name to Seleucus after he succeeded his father as King. After a brief reign of three years (225–223 BC), Seleucus was assassinated in
Anatolia by members of his army while on campaign against
Attalus I of Pergamon. His official byname
Soter means "Saviour", while his nickname
Ceraunus means "Thunderbolt".