The Amateur Cracksman

A. J. Raffles and his friend "Bunny" Manders are the quintessential rich young socialites ; but behind the high-living façade, they've exhausted their funds. There's only one way to pay the bills : a secret double-life as criminals. Raffles was E. W. Hornung's biggest literary success, with the Raffles stories proving perennially popular. This volume was dedicated to his brother-in-law Arthur Conan Doyle, and in Raffles and Manders there is a clear relation to Holmes and Watson.
The character's popularity helped kickstart the "gentleman thief" genre, and it's easy to see parallels to the later stories of Arsène Lupin by Maurice Leblanc.