Unlike a standard dry memoir, Legionar is often described as a "dynamic and direct" piece of fiction or semi-biographical prose. The story follows a young officer who, after graduating from the prestigious , enters the French Foreign Legion —the ultimate dream for many cadets. The book explores:

The popularity of the book cannot be separated from the turbulent history of the 1990s. The Special Operations Unit (JSO), which Ulemek commanded, was a state-sanctioned paramilitary force known for its effectiveness and brutality. The JSO has been linked to numerous war crimes and criminal activities.