Short answers, pulled from the story.
The name Soho first appears in records around 1636 and is derived from a former hunting cry. James Scott, the 1st Duke of Monmouth, used "soho" as a rallying call for his men at the Battle of Sedgemoor on the 6th of July 1685, about half a century after the name had already been attached to the district.
Physician John Snow identified the cause by mapping the addresses of the sick and tracing them to the public water pump at the junction of Broad Street (now Broadwick Street) and Cambridge Street (now Lexington Street). He persuaded the authorities to remove the pump handle, halting the outbreak. A replica pump without a handle was erected nearby in 1992.
Trident Studios at 17 St Anne's Court was established by Norman and Barry Sheffield in 1968. The Beatles recorded tracks from The White Album there, Queen recorded their first four albums at the studio, and David Bowie, Elton John, Free and Thin Lizzy also recorded there. The studio closed as a general recording facility in 1981.
The Windmill Theatre on Great Windmill Street was known for its non-stop variety shows and nude tableaux vivants, and for claiming to be the only London theatre that did not close during the Second World War, adopting the slogan "We never closed." Harry Secombe, Jimmy Edwards and Tony Hancock all began their careers there. It closed on the 31st of October 1964.
At its peak between 1976 and 1982 Soho had 54 sex shops, 39 sex cinemas and cinema clubs, and numerous other adult venues. A combination of police reform following corruption trials in 1975, pressure from the Soho Society founded in 1972, and tighter licensing by Westminster City Council reduced the number of sex industry premises from 185 in 1982 to around 30 in 1991. By 2000 the trade had been further reduced by relaxed censorship, internet competition, and gentrification.
On the 30th of April 1999, the Admiral Duncan pub on Old Compton Street was damaged by a nail bomb that killed three people and injured 30. The bomb was planted by David Copeland, a neo-Nazi who was carrying out a series of attacks aimed at stoking ethnic and homophobic tensions in London.