Children's chapter books. There are so many with a backdrop of WW2 and sometimes WW1. They seemed to begin a generation or two ago, with books like Carrie's War, Machine Gunners, Goodnight Mr Tom. They are still being published today- Letters from the Lighthouse, etc.
Is this the case in France, Germany, Italy, other countries? Does anyone know, or have any examples? Or is it a British thing?