The inspiration behind the novel is Walter Tull, Britain's first black Army officer to lead white British troops into battle.

He learns that his grandfather was a football player before he joined the army, and he was killed in action in Belgium, and soon after his death, she finds out she is pregnant with his father Roy, and ends up raising him alone as an unwed mother.

Michael also discovers that his father Roy, at the age of nineteen, joined the British military, and became a pilot for the Royal Air Force, and was stationed in France for a time, which is where he met Christine, his mother, and they were married shortly thereafter.

One of his granddaughters, who is named Christine, after learning the story of her great-great-grandfather Leroy, says how unfair it was that he never received a medal for his heroic actions in World War I, so her and Michael begin a campaign to get him recognized with an award.

[3][4] Walter Tull was the first British born black army officer, and an English professional footballer, who played as an inside forward and half back for Clapton, Tottenham Hotspur and Northampton Town.

[7] In a letter of condolence to his family, the commanding officer of the 23rd Battalion, Major Poole and his colleague second lieutenant Donald Henry Pickard both said that Tull had been put forward for a Military Cross.

[8] In 2018, David Lammy, then a MP for Tottenham, wrote a letter to prime minister Theresa May and secretary of state for defence Gavin Williamson, requesting that his Military Cross be awarded posthumously to mark the centenary.

O'Connor also opines that the novel "highlights race as a factor worthy of historical notice; and then also suggests that racism is of little significance to black people in the past and completely absent in modern-day life.

She contends that despite the fact Michael was actually born in England, he isn't really thought about as being truly English, but only 'English enough', because he can be easily identified by sight as being racially different from his white classmates.

[11] Elizabeth Hawksley from the Historical Novels Review wrote "this book is about family secrets and the cost of keeping them hidden; it's also about the emotional adjustments that must be made when the truth comes out; it is a moving story, sympathetically illustrated by Michael Foreman".

[15] Daniel Kraus wrote in The Booklist, "it's a fine story, even if Leroy's goodness is a bit too perfect to be believed; in fact, the entire book is squeaky-clean, which may make some eyes roll, even while being that warm, gentle read that others savor".

[16] Lorna Bradbury of The Daily Telegraph noted that "as ever with Morpurgo, the most lasting relationships are with the animals, in this case a Jack Russell, illustrated by Michael Foreman".

[19] Margaret Pemberton wrote in School Librarian that "the slow build up revealing relationships, together with emotional pulls, make for a gripping story ideal for junior ages and provoking both thoughts and questions".