The story is told as a fictional account of one of the soldiers, based on the author's uncle, though including many historical facts.
This cub who they called Wojtek (pronounced Vojtek), meaning 'Happy Warrior' in Polish, was initially adopted as their mascot and would be raised by their company, accompanying them on their travels through the Middle East. It would then be given official documents by the authorities making him a real soldier (hence the term Private) so as to enable him to travel with the company to the battle of Monte Cassino, where he would become a hero.
After the war, Wojtek came to Scotland with the soldiers and, after being demobbed, had to be given to Edinburgh zoo.
He was a huge, comical, tame and intelligent bear and had many hilarious adventures during his time with the Company.