I didn't do a whole lotta reading in 2020, mostly because work was closed and that's where I do 99% of my reading.
Highlights this year include a book called The Butchering Art, which was largely a biography of Joseph Lister, and the evolution of Victorian era surgery. Lister was a Quaker surgeon who pioneered the application of germ theory and sanitation to surgery. Apparently it was a very interesting time medically; before there was no anesthetic either, so surgery was a speedrunning affair, and more importantly was rather rarely done. Anesthetic was just invented at that time, which gave doctors a lot more confidence in surgery, but nonetheless it was still very dangerous and survival was unlikely.
There was also the 'Four Londons' (my name for it) trilogy, although I have not finished the final book. A Darker Shade of Magic was the first book. It involved four parallel dimensions, each conveniently having some sort of major city where London is geographically, and each having a different level of magic and a different relationship with said magic. Gray London was the normal Victorian London, where magic was dead and forgotten. Red London is a high fantasy world with commonplace magic and magic technology, the river Thames being a massive magical leyline. White London is war torn and nearly barren, magic is seen as a resource which was overly exploted for quick and easy power, its leadership ultimately being whomever is the most mighty. Much of their desolation was caused by fighting off whatever leaked from Black London, a sealed off apocalyptic hellhole where magic ran rampant and consumed all life as we know it. The main character is a guy who is one of very very few born with the power of blood magic, allowing him to travel between the worlds. The idea of there even being other worlds is only really known to people like the main character (there's like four) and the royalty of each world.
I also read a book on the history of Samurai, which basically means the overall military history of Japan from early oral history to the sino-russian war. Hollywood depictions of samurai really only reflect on the very tail end of samurai history, when Japan was largely peaceful and isolationist, so a warrior caste had not much better to do than duel, wax poetic, and govern. Most of the time they were just notable warriors who owned land or whatever, the idea of them being honorable wasn't particularly true outside of suiciding the whole family instead of facing defeat. They also really didn't mind guns at all and spent no time buying them from the Dutch.
One thing to do this year: I borrowed the JSA Omnibus from a friend, its an entire run of JSA, and the book's like two three inches thick. Need to actually finish it at some point soon to give it back, as I don't really enjoy having a 100$ book that isn't mine lying around.