Third time around. Prompted by Andrew Delbanco's review of a Kubrick biography that suggests this was Kubrick's take on Napoleon. I hadn't realised it was based on a book by Thackeray. Things go precisely parabolically. The movie is somehow both soporific and entirely gripping which might be due to the cinematography or perhaps Marisa Berenson. Amazingly still #200 in the IMDB top-250.
Roger Ebert at the time (3.5 stars; key phrase "ultimately inconsequential") and as a "great movie" (an automatic 4 stars in 2009). Vincent Canby.