"Gentlemen of the Shade" is a fantasy story by Harry Turtledove, originally published in Ripper!, Gardner Dozois & Susan Casper, eds., Tor, 1988. It was reprinted in the Turtledove collection Kaleidoscope in 1990 and in The Big Book of Jack the Ripper (Otto Penzler, ed., Vintage Crime/Black Lizard Original) in 2016.
The story is a secret history that posits Jack the Ripper was a vampire. Jack comes to the attention of an elite club of British vampires, known as the Sanguine Club. Although currently living in VictorianLondon and adhering to British cultural norms, the vampires of the Sanguine Club are quite old. They feed humanely on blood from the dregs of society, in a way that does not hurt these people. However, the relatively young Jack relishes his undead powers, preferring to brutally mutilate his victims instead of merely feeding from them, committing the canonical Jack the Ripper Murders. The Sanguine Club pursue Jack, finally capturing him in November, 1888, and brick him up in the foundation of the Tower Bridge, dooming him to be forever shielded from the sun's rays yet ever unable to feast as punishment for his crimes.