The story focuses on the harsh realities of English rural life and warfare, and highlights the British Army's practice of executing its own soldiers during the First World War.

The story is told from the perspective of the fictional character Thomas "Tommo" Peaceful, a young man from a rural village in England who fights in the First World War.

Each chapter indicates the progress of time, with titles such as "Five Past Ten" and "Twenty To Eleven", gradually counting down to the morning of his brother Charlie's execution by firing squad.

Tommo, Charlie and Molly grow up together; their mischievous adventures include braving their nasty great-aunt, defying a Colonel, skinny-dipping, and being the first people in their village to see an aeroplane.

The rest of the story describes the brothers' experiences of the war: their confrontations with Sergeant "Horrible" Hanley, near-misses during the fighting on the front line, and Charlie's continued protection of Tommo.

During a charge of the German lines, Charlie disobeys a direct order from Sergeant Hanley and stays with Tommo while he is injured in no-man's-land.

Charlie is marched before the firing squad and dies happily, singing his favourite childhood song, "Oranges and Lemons".

[1] Compared to other twenty-first-century children's novels about war, which often focus on families and civilians' perspectives, Private Peaceful is about how soldiers were also victims of the time.

Morpurgo was inspired to write a novel about soldiers who were court-martialled and shot during the First World War after learning about the practice whilst at a conference in Ypres.

After facing calls to review the executions, in 1998 the Ministry of Defence denied there was a need to grant posthumous pardons to the approximately 300 men who had been killed.

[8] The UK Government did acknowledge that the executions were wrong, but continued to refuse pardons due to the complexities of reviewing the historic cases.

[10]Morpurgo has said that inspiration for the plot of Private Peaceful came from the story of Sergeant John Thomas Wall, who was executed for desertion on 6 September 1917.

During an enemy artillery barrage on 10 August 1917, Wall was sheltering in a dugout with two privates and refused to leave them behind, knowing that attempting to re-join the front line would have led to certain death.

[8] The origin of the name "Peaceful" for the novel's title character came from a gravestone at Bedford House Commonwealth War Graves Commission Cemetery near Ypres.

Peaceful, the inspiration for the novel's name, in Bedford House Cemetery, the man's background was not known; Morpurgo said of him "He's as close to an unknown soldier as you can get".

A new headstone bearing the correct name was installed in July 2018 by the Commonwealth War Graves Commission, with Keeble, her husband, and Michael and Clare Morpurgo, as witnesses.

[12] The book was adapted into a play of the same name by Simon Reade, first performed at the Bristol Old Vic in April 2004 starring Alexander Campbell.

[22] At a 2012 production of the play at the Theatre Royal Haymarket, 306 names of men who were shot for cowardice, desertion and other related crimes were listed on the back of the programme.

Dominic Cavendish of The Telegraph wrote that "Costello evokes a sturdy boyishness while eschewing male-impersonation – emblemising a spirit of youthfulness and hopefulness".

[30] A feature film version of Private Peaceful, directed by Pat O'Connor with a screenplay by Simon Reade, was released in October 2012.

[34] It deviates from the book in that Tommo goes to the Front before Charlie, who resists the war due to political reasons and not wanting to leave behind his pregnant wife.

[22] Kate Stables of the magazine Sight & Sound described the film as "a small and intimate affair",[34] and Peter Bradshaw of The Guardian wrote that it was "a small-scale story in essence, which works efficiently on the non-epic in which it's presented".