Analyst and author Stuart Slade just passed away.
His The Big One books were some of the first “niche” AH (as in, not stuff that you could see in normal booksellers like Harry Turtledove) that I read. For all my criticism of them, they played an undeniable role in getting me into, for lack of a better word, “weird alternate history”. They were among the first pieces of alternate history I read that weren’t from mainstream authors like Turtledove. I liked the weirder gimmicks inside them.