The Just William series by Richmal Crompton
"The William Brown series, better known as the Just William series, is a series of thirty nine books written by English author Richmal Crompton. The books are based around the mischievous schoolboy William Brown .
Published over a period of almost fifty years, between 1921 and 1970, the series is notable for the fact that the protagonist remains at the same eleven years of age, despite each book being set in the era it was written in. The first book was Just William, and often the entire series is named after this book. Each book, with the exception of Just William's Luck, which was a novel, was a collection of short storie"