Seleucus III Ceraunus in Wikipedia
Seleucus III Soter, called Seleucus Ceraunus (Greek: Σέλευκος Γ' Σωτὴρ, Σέλευκος Κεραυνός 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 changed his name to Seleucus after he succeeded his father as King. After a brief reign of three years (225 BC-223 BC), Seleucus was assassinated in Asia Minor by members of his army while on campaign against Attalus I of Pergamon. His official byname "Soter" - Greek: Σωτὴρ means "Saviour", while his nickname "Ceraunus" - Greek: Κεραυνός means "Thunder".
Seleucus in Harpers Dictionary of Classical Antiquities (1898)
Surnamed Ceraunus (226-223), eldest son and successor of Seleucus II. The surname of Ceraunus ("Thunderbolt") was given him by the soldiery, apparently in derision, as he appears to have been feeble both in mind and body. He was assassinated by two of his officers, after a reign of only three years, and was succeeded by his brother, Antiochus the Great.