Queering Holmes

This post is riffing off wrabbit's suggestion in the discussion prompt gathering thread, which is still taking suggestions for new discussions if you have them.

Holmes and Watson weren't the first detective/sidekick duo, but they were one of the earliest pairs to achieve enormous popularity. Since then, similar pairings/duos have become a recognisable type in pop culture.

What are the distinctive traits of the Holmes/Watson pairing? Who are some of the more recent pairings/duos that draw on H/W? wrabbit mentions House and Wilson, of course, but it seems to me that the very common pairing of an exceptional/brilliant and possibly anti-social hero with a partner who's a stabilising influence or a source of exposition or both, owes a lot to H/W. There are plenty of detective duos, of course, especially on television. When wrabbit posted her comment I thought of Jim/Blair from the Sentinel (a police detective with an academic partner), and then last night, watching Hornblower with a friend, I realised that Archie is a bit of a Watson in a way: he exists in the TV canon to make Hornblower less solitary and internal and help the story move along, is Horatio's best friend with whom he shares everything, and is loyal and straightforward to Horatio's awkward brilliance. C. S. Forester didn't originally write Archie as a partner for Horatio in the book series, and Bush (who shows up later in the chronology of the series) doesn't fit the H/W pairing mold at all, but perhaps by the 90s when the TV writers came to develop Archie as Horatio's partner, that type of pairing had become more standardised?

H/W has also been called the archetypal slash pairing and the first slash fandom (btw, does anyone know whether anyone was actually publishing H/W slash in zines before Star Trek slash came along?) If the H/W pairing is a discernable "type", is that type inherently slashy or queer? How many H/W-influenced pairings have considerable slash followings?