is the first published book of the incomplete Childe Cycle series of science fiction novels by American writer Gordon R. Dickson.

A re-edited and expanded version of the novel was published under its original serialized title, Dorsai!, by DAW in 1976.

Donal is a member of the Dorsai, a splinter culture based on the planet of the same name, which has specialized in producing the very best soldiers.

Leaving William's command, he embarks on a series of operations in different conflicts that mark him as an innovative genius.

In the final chapters, Donal achieves something previously thought impossible: the invasion and conquest of a planet, William's home world.

is of characteristics said to be typical for science fiction books of the era, including "wooden dialog and rampant misogyny".

In the popular 1990s computer game Star Control II, one of the melee captains for the (human) Earthling Cruiser is named "Graeme", alongside other recognizable human science fiction captain names including "Kirk", "Decker", "Adama", "Solo", and "Buck".