One of the best movies that I can hope to see. I don't think it tries to replicate real life events, but it seems to be very realistic. Churchill isn't shown to be heroic, or a shining star. He is shown confronting or cajoling people wherever he is, including when he is with his own family. I don't feel any empathy or sympathy for his role, because he accepts his lot that comes his way, even if it is unpleasant.
Apparently, at the start of the Second World War, his biggest adversary is not Hitler, but people like Lord Halifax (?), and another person, who want him to make peace with Germany. This movie is about how he prevails over them. The King of England is one of his strong critics, but becomes his strongest supporter. At the end of his first audience with the King, the King offers his hand to Churchill to kiss, but then wipes his hand on his own back after Churchill complies.
I don't want to give any more away, but if you want to see a war movie without the fighting with guns, then you may really appreciate this movie.