Darkest Hour (2017)
Holy hell, fat Gary Oldman! But not to worry, that's just a lot of makeup, he had to don for playing the role of Churchill.
The movie deals with basically the first month of his rule as Prime Minister, during the seemingly unstoppable German march. It's all very dramatic, and, interestingly enough, Dunkirk events are also part of this, as this is the military operation they were concerned with the most at the time.
Now, the usual site tells us, that while there are many relation with true events and general feeling of the time, a lot of over-dramatizations were made. Most of the movie, actually, as Churchill's secretary, given strong role in the movie, was not in his employ at the time, yet, they didn't, again, at that time, use the underground war rooms, and if the meeting with people ever took place, it was not like it depicted in the movie. Many things were over-dramatized, many were sped up for the narration purposes, so this movie cannot really be shown as true representation. They do say, that the man really did have a nasty personality at times, so there's that.
Still, big movie, and interesting for what it is. Also, really, fat Gary Oldman, gotta watch it at least for that.