E.C. Tubb 
The Stellar Legion 

Wilson, an unwanted waif of the generation-long war of unity, spends his boyhood in forced labour and persecution. Rebelling, he is sent as a convicted murderer to the newly colonised penal world of Stellar. He survives to win promotion in the Stellar Legion, the most brutal military system ever founded.

Laurance, Director of the Federation of Man, is afraid of the thing he has helped create, and tries to dissolve the Stellar Legion. He pits his wits against its commander, Hogarth, terrified lest the human wolves trained and hardened in blood and terror should range the defenceless galaxy…