is said to be between the dog and the wolf; “betwixt and between,” neither day nor night; a breed between the dog and wolf; too much day to be night, and too much night to be day. Probably the phrase was suggested by the terms “dog watch” (which begins at four), and “dark as a wolf's mouth.”
Sicilian Vespers. Easter Monday, March 30, 1282. So called because John of Procida on that day led a band of conspirators against Charles d'Anjou and his French countrymen in Sicily. These Frenchmen greatly oppressed the Sicilians, and the conspirators, at the sound of the vesper bell, put them all to the sword without regard to age or sex.
The Fatal Vespers. October 26th, 1623. A congregation of some 300 persons had assembled in a small gallery over the gateway of the French ambassador, in Blackfriars, to hear Father Drury, a Jesuit, preach. The gallery gave way, and about 100 of the congregation were precipitated into the street and killed. Drury and a priest named Redman were also killed. This accident was, according to the bigotry of the times, attributed to God's judgment against the Jesuits. (Stow Chronicles.) (See St. Luke xiii. 4.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894