It tells of the adventures of John Gordon, a 20th-century man who is transported 200,000 years into the future and finds himself inhabiting the body of Prince Zarth Arn of the Mid-Galactic Empire just as war and intrigue breaks out.
Hamilton returned to the setting in the 1960s, writing a series of short stories about John Gordon's further adventures that were collected in the book Return to the Stars. He and Leigh Brackett also collaborated on a one-off Crossover with Brackett's Eric John Stark series, "Stark and the Star Kings".
This series contains examples of:
- Affably Evil: Shorr Kan, the Big Bad of the first novel. In fact he is so affable he's brought back for the sequel as an ally.
- Anti-Hero: Shorr Kan again, after his HeelFace Turn.
- As You Know: The hero of The Star Kings, a twentieth century man transposed into the body of a Prince of the Mid-Galactic Empire, is desperate for these but the other characters just won't oblige.
- Blob Monster: In the first book, a ship makes a crach landing and is attacked by these. Apparently, some local radiation affected a human colony.
- Body Swap: The whole thing starts when Prince Zarth Arn swaps bodies with John Gordon.
- Conveniently-Placed Sharp Thing: In The Star Kings, the hero, while prisoner on the enemy ship, is tied up in a chair. However, a battle forces a crash landing, which cracks the chair just enough for the hero to saw through his bindings after half a day or so.
- Costume Porn: Averted. Hamilton's Star Kings, Princesses and heroes wear simple, comfortable jacket and trouser suits, rarely accessorized with a flowing cloak or flashy jewelry.
- Defrosting Ice Queen: Lianna of Fomalhaut.
- Enclosed Extraterrestrials: The H'harn are completely covered with cloaks whenever interacting with humans. The reason becomes obvious when one undresses to Mind Meld with the protagonist.
- Eternal English: Downplayed, since the language of the future is not the same as modern English. However, it is still based on English, and can be learned quite fast by a modern man. Quite reasonable — except we are talking about 2000 centuries in the future.
- Feudal Future: The title The Star Kings says it. John Gordon, transported into this future from the twentieth century, is somewhat disappointed to discover the far future is monarchical until reassured that they are constitutional monarchies.
- Holodeck Malfunction: In The Star Kings, the League's secret weapon used a similar principle. During a battle, Cloudmen would tap the "telestereo" beams used to communicate and insert recordings of shooting weapons. The energy output would be enough to destroy everything on the bridge within sight of a receiver, putting the ship out of battle or making it a sitting duck. Looks like telestereo receivers were built unreasonably powerful. Fortunately, all ships already had countermeasures — portable dampers that can suppress the shots leaving the receiver pad — and started using them when the hero figured out how the weapon worked. Either the League was not the first to invent those, or they need them for reactor leaks..
- Interrogated for Nothing: The main character is subjected to a Mind Probe to get details about a superweapon. Twice. The first time, it fails because he is not the man the villain was looking for (they switched bodies). The second time, the aliens probing him are actually aware he's not the right person — but they do know he had to use the weapon, so they probe him for details of its workings. They even resort to a Mind Meld when a normal probing fails to show any details. Since all the hero knows is which buttons to push, all it does is reveal the location of their fleet.
- Lilliputians: The second book has a planet with the remnants of a human colony. Some local factor mutated them into barely foot high beings.
- Mental Fusion: In Return to the Stars, alien invaders resort to that in order to get details about a superweapon after a normal Mind Probe fails to get them from the main character. Since all he knows is how to use it, they don't learn anything useful... but the hero learns the location of their fleet.
- Mental Time Travel: The premise of the first book.
- Mind Probe: The protagonist is captured by a villain, who tries to extract a valuable secret from him with a Mind Probe. According to the villain, a few hours would have left him a mindless husk, but since the first minute showed the subject is not the man they're looking for, he got away with just a very severe headache.
- Orwellian Retcon: In the original ending of The Star Kings, the hero returned to his own time and body, and his love followed him some time later by swapping bodies with an incurably comatose girl. Once Hamilton wrote the sequel, that changed to her contacting him telepathically and saying they are working on a way to transport him into her time physically. For some reason, however, some recent printings still include the original ending.
- Princesses Rule: For some unexplained reason the ruler of the Star Kingdom of Fomalhaut uses the title 'Princess' rather than 'Queen'.
- Ready for Lovemaking: John Gordon finds Murn, the morganatic wife of the prince whose body he is currently occupying, in his — or rather Prince Zarth's — bed wearing nothing but a transparent negligée.
- Scenery Porn: The silver seas and crystal cliffs of Throon are an especially plangent example.
- Shining City: The capital of the Mid-Galactic Empire is built of glass upon shining silica cliffs above a silver sea; with a hot white sun like Canopus overhead the citizenry must have to wear shades.
- Straw Hypocrite: In The Star Kings, when the heroes are brought to the villain, he tells the one who brought them about how they will soon crush their oppressive enemies... Blah blah blah. After the guy leaves, he asks the hero "How did you like my little speech?", and at his amazement, explains that he's no idiot, and such speeches are only useful for mindless fanatics. But since that's the main driving force of his conquest... Well, he has no choice.
- Time Travel Romance: In The Star Kings, a person from the 20th century swaps bodies temporarily with a prince from the far future. While there, he and a princess fall in love with each other (the princess is in love with him, despite being unaware of the body swap). In the original ending, after he returns to the 20th century, she travels back to be with him; for the sequel, the ending was retconned so that a way was found for him to join her in her time.