Are There Any Real Rivals to Sherlock Holmes?

My bookshelves contain several books with the words "rivals" and "Sherlock Holmes" in the title.

Most famous of them, perhaps, are The Rivals of Sherlock Holmes and Cosmopolitan Crmes: Foreign Rivals of Sherlock Holmes. Both were edited and introduced by Hugh Greene who also produced The Further Rivals of Sherlock Holmes and The American Rivals of Sherlock Holmes. Greene also created a British TV series called "The Rivals of Sherlock Holmes" in the early 1970s.

Next his books on my shelves are the similarly named Rivals of Sherlock Holmes and Rivals of Sherlock Holmes 2, selected and introduced by Alan K. Russell from The Strand and other magazines of the late Victorian era.

Speaking of Victorian, I also have A Treasury of  Victorian Detective Stories, edited by Everett F. Bleiler. That one doesn't use the "rivals" gimmick, although it could have.

And yet . . . Does Sherlock Holmes really have any rivals? I think not!

He had many contemporaries, but their names are almost forgotten today. When was the last you curled up with tthe adventures Loveday Brooke, Lady Detective; Martin Hewitt, Investigator; Professor S.F.X. Van Dusen, the Thinking Machine; Romney Pringle, literary agent and thief; or even Dr. Thorndyke, “the greatest medico-legal detective of all time” (Penzler and Steinbrunner) but little remembered today?

But Sherlock Holmes is far from forgotten, nor is his memory kept green only in the nostalgic hearts of  a small coterie of followers. He is as famous today as he ever was, if not more so. The 21st century finds him riding a new wave of popular culture stardom -- by one count, his seventh. No other sleuth of fact or fiction comes close to his stature as an icon of what it means to be a detective. 

Rivals to Sherlock Holmes? What ineffable twaddle!