He was born in Kirkby Overblow (as mentioned in Hare Sitting Up) and brought up in a back street in a Midlands town (Appleby's Other Story).
He retired from Scotland Yard at a very early age just after World War II, on marrying Judith Raven, a sculptor first encountered in Appleby's End.
Although he later retired to Long Dream Manor, his wife's family home in the countryside, he continued to solve crimes well into the 1980s, his last appearance being in Appleby and the Ospreys in 1986, 50 years after his fictional debut.
Appleby is mentioned in the Edmund Crispin novel Holy Disorders and the Isaac Asimov Union Club short story "The Three Goblets."
A Connoisseur's Case and Lesson in Anatomy were adapted for the 1960s BBC anthology series Detective, with Appleby being played by Dennis Price and Ian Ogilvy, respectively.