Triplanetary (1948) by E.E.Smith

Wikipedia wrote:Triplanetary is a science fiction novel and space opera by E. E. Smith. It was first serialized in the magazine Amazing Stories in 1934. After the original four novels of the Lensman series were published, Smith expanded and reworked Triplanetary into the first of two prequels (the second prequel was a new original novel, First Lensman). It was published in book form in 1948 by Fantasy Press.

The novel covers several episodes in an eons-long human breeding project by the super-intelligences of the Arisians. This alien race is breeding two genetic lines to become the ultimate weapon in Arisia's cosmic war with their arch-enemies, the Eddorians. The initial chapters cover the Kinnison genetic line during the fall of Atlantis and Nero's reign in Rome. These tales were inserted into the novel following the serialized release, along with chapters covering members of the Kinnison line in World Wars One, Two, and Three.

The final chapter of Triplanetary tells of the discovery of the inertialess drive that allows faster-than-light travel. Patrolman Conway Costigan and his friends engage in a space battle with Gray Roger the pirate gangster. This conflict is complicated by the arrival of the technologically superior, extra-Solar, amphibian-like Nevians, resulting in the first interstellar war involving humans. In this story Virgil Samms and Roderick Kinnison, important members of the two breeding lines, are introduced.

Wikipedia wrote:Triplanetary is a prologue to the Lensman series. It consists of two parts. The first explains the series background, which consists of a conflict between the evil Eddorians and the benevolent Arisians. This conflict is carried out throughout the history of an oblivious humankind on Earth. The Arisians undertake a eugenics project to breed two human genetic lines that are intended to become the ultimate weapon in Arisia's cosmic war with Eddore.

The author takes five defining chapters to cover the background of the Kinnison line: the destruction of Atlantis in a nuclear war, an attempted coup in Rome against the Eddorian-controlled Nero, the First and Second World Wars, and, finally, a nuclear Third World War. In each of these periods he tells part of the story of the two families who will be of importance later on, and who will produce the two people whose children will be the culmination of the human breeding line, Kimball Kinnison and Clarissa MacDougall. One genetic line is surnamed "Kinnison" or some close variation. The other line is distinguished by having "red-bronze-auburn hair" and unusually colored "gold-flecked, tawny eyes".

The final part of the book, which was originally published as a magazine story, takes up the tale after civilization has been rebuilt with the covert help of the Arisians. Humanity has explored the Solar System and formed the Triplanetary League, which consists of an alliance of Earth with the governments of Mars and Venus. Prior to the start of the main story, humans have set up in-system colonies and fought the first interplanetary war against the Adepts of North Polar Jupiter.