AustLit

Prince Milona (Son of the Stars), who has accompanied his father King Amando to earth on an interplanetary flight from Mars, wanders off into the Australian bush while their spaceship is being repaired. He falls into a stream but is saved from drowning by two English boys, Bruce Mortimer and Maurice Summers, who were herding sheep nearby. The three become friendly, which leads to Milona helping Bruce and Maurice, along with Mike (an "ethnic comic character") stowing aboard the craft. When their presence is discovered en route the three humans are allowed to continue the voyage. After arriving on the planet, however, the ship is attacked by rebel forces led by the scientist king, Faronda. The boys and Prince Milona are subsequently thrust into a series of adventures as they try to help overcome Faronda and another evil Martian king, the tyrannical Zandalla. After King Amando's forces eventually prevail, the boys are returned to Earth.

[Source: Everett Bleiler, Science Fiction: The Early Years (1990), 22-23]