Reporter Johnny Mann was covering a civil war on the Greek island of Cyprete, when he visited the ruins of the Hall of Jupiter. After pondering why the "gods" allowed so much war and killing, he suddenly found himself transported via thunderbolt to Mount Olympus.
Johnny was in the presence of Jupiter, Mars, Venus and Vulcan and so he boldly let them know what he had been thinking about the evils of war. The Olympian "gods" said they were not responsible for man's evil ways, and so they would not deal with it.
Mars was all for killing this human upstart, but Vulcan defended him for his courage and Jupiter allowed Vulcan to give Johnny any weapons he needed from his arsenal. It would be Johnny's task to fight this evil he had complained about. Venus gave Johnny, who had a wooden leg from a war injury, a muscular body - and the Son of Vulcan was born.
Johnny proved to be resourceful in his battles and once even fought Mars himself, as the god of war sought revenge on Johnny and his peace seeking ways. Mars even allied himself with Doctor Kong in an attempt to overcome the son of Vulcan, but once again failed.
The Greek Gods and Roman Gods were waging a war over whose champion was the strongest. THe Roman Gods wanted the Son of Vulcan to be their champion against the Greek Gods champion Wonder Woman. He refused and the Roman Gods chose Captain Marvel to be their champion in the battle. The Son of Vulcan was investigating the cause of the war and met Harmonia, daughter of Ares. She was also investigating the cause. They learned that the sorceress Circe was behind the war and her plan was to gain divine power. Son of Vulcan and Harmonia fell in love and died in battle. His soul, was apparently, taken to Elysium.
The Son of Vulcan made one last appearance and gave up his mantle and power to the teenaged Vulcan before returning to Elysium.