The Masquerades of Spring is the latest novella by Ben Aaronovitch. It takes place in the Rivers of London universe, but is set in Harlem, New York, in the 1920s. As with the longer RoL books it has a first person narrator, in this case Augustus "Gussie" Berrycloth-Young, a young Englishman living in New York. He was a contemporary of Thomas Nightingale at Casterbrook School, where young British gentlemen of the magical persuasion have been educated for generations, and was connected with the Folly (headquarters of the Society of the Wise) but is now a man of leisure, enjoying a life of jazz clubs, parties and gay hedonism.
The book is many things - an affectionate pastiche of Jeeves & Wooster by P.G. Wodehouse (Gussie is a nod to Gussie Fink-Nottle, Jeeves is represented by Berrycloth-Young's valet, Beauregard), a detective story, an LGBT love story, a paean to the roaring '20s and the jazz age, and a celebration of the resilience and creativity of the people of Harlem. There is some magic, after Thomas Nightingale turns up in search of an enchanted trumpet and a friend of the Folly's maid and housekeeper Molly, another Fae who needs to be rescued.
There is lots to be enjoyed here, so if you are a fan of Peter Grant and Thomas Nightingale in the full-length RoL books then this is going to be right up your alley. At the back of the book there is what appears to be a spoof of those publishers' advertisements for other books, with descriptions of more Gussie & Beauregard stories which seem not to exist, but perhaps they are a teaser for further volumes yet to come? That would be something to look forward to.
By the way, have you ever wondered why the headquarters of the Society of the Wise, the centre of British wizardry, is called the Folly? It's actually a reference to the poem Ode on a Distant Prospect of Eton College, by Thomas Gray.
Good point. The English civil war and the French revolution both went the way they did because the 'rebels' had armies which equalled or exceeded those of the government. Same with the other regicide that comes to mind, Nicholas II of Russia in 1918. So much depends on whether the military remains loyal.