Hoover's geneticist wife, Elizabethan, knew that he was sterile. So to have children, she obtained genetic material from Hanstrum to impregnate herself. Thus, he was the father of Asia, Africa and Antarctica. Hanstrum considered the children his, so when Elizabethan told Hanstrum that she planned to tell her husband the truth about the triplets, Hanstrum killed her.
When they were older, he tried to convince them to kill Hoover, then let him rule New Jupiter as regent until they were old enough to take over on their own. They refused and had him put in a dungeon in the Medieval Zone of EarthWorld. (PROSE: EarthWorld)