Sivana, with his children Sivana, Jr and Georgia. Interior art from The Marvel Family #10 (1947), by C. C. Beck and Pete Costanza. Thaddeus Bodog Sivana, born in 1892, began with the best intentions and was one of Europe's best scientific minds, with progressive scientific ideas that could revolutionize industry but were rejected by everyone he approached.
Laughed out of society by people who called his inventions impractical and his science a fake, Sivana took his family to the planet Venus in a spaceship he had invented. There he stayed until his children were grown, and Earth not as backward as when he left it. (Since his children were adults by 1940, his departure from Earth would implicitly have been the late 1910s or early 1920s.) During his years away, struggling to tame the Venusian jungle, Sivana turned bitter and planned his revenge against the world that had shunned him. He initially plotted his revenge with a radio silencer that would disable all radio communications permanently.
He tried to extort $50,000,000, only to be stopped by Captain Marvel in his first adventure. Cap broke through the window of the building where Sivana was hiding and defeated the guards, binding them securely with tubing ripped from the radio-silencer. Sivana planned to kill Captain Marvel with a blast from his Atom-Smasher, but Cap leaped back out the window and escaped. During the fight, Sivana's returning army angrily asked why Captain Marvel had defeated them in their war against America despite their highly advanced weaponry.
Sivana appeared to have been killed by the Atom-Smasher blast, but he returned a short time later, having somehow learned Captain Marvel's identity. He sent a letter to Billy Batson to lure him to the planet Venus, disguising himself as 'Professor Xerxes Smith'. Sivana's henchmen bound and gagged Batson, and Sivana tried to take away his memory using a Memory Mangler.
Billy regained his memory after stumbling into the cave of Shazam and accidentally saying the word "Shazam". Sivana's henchmen rebelled against him and set off an explosion that destroyed the Mangler. Ironically, Captain Marvel saved Sivana and his daughter Beautia, who the henchmen had left to die. Sivana continued to nurse a megalomaniacal grudge against humanity and also a personal enmity with the Marvel Family. This persisted even after Cap revealed Sivana's former benevolent inventions (which Sivana considered useless), leading to his being awarded the Nobel Prize for Physics. Far from being pleased, Sivana was insulted by the prize and stated that only when he was crowned Ruler of the Universe would he consider himself properly honored.
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