MOCK biographies of fictional characters have long been a staple joke of publishers. But they don't come much better than this 'unauthorised' biography of the great Victorian detective.

Rennison plays by the rules, never once admitting the subject of his book wasn't a real person. There is surprisingly little information about Sherlock Holmes' life for the biographer to draw on, he concedes - so he is forced to rely on the accounts of Holmes' exploits penned by his friend Dr John Watson. These, the biographer says, are highly selective (Watson chose only a minority of Holmes' cases to write down) and also sometimes biased. Nevertheless, they provide a great insight into the man.

In Rennison's hands, they certainly do. The author shows how Holmes held sway over key political events of the late 19th century, and reveals his deep connections with the criminal underworld - from his involvement in the plot to assassinate Queen Victoria to his - unacknowledged - solving of the Jack The Ripper murders.

Updated: 16:37 Friday, December 09, 2005