Winston Churchill starred in three movies in 2017. First came Churchill in June, a critically panned biopic that pictured a beleaguered Churchill, played by Brian Cox, awaiting the Battle of Normandy. About a month later, in July 2017, came Christopher Nolan's war epic Dunkirk, which takes place days after Churchill was sworn in as Prime Minister. Though Churchill is not actually in Dunkirk, his presence is felt. And though the battle of Dunkirk is not actually depicted in The Darkest Hour, a November 2017 movie about Churchill's early days, his looming presence is similarly palpable.
You could say this trio of Churchill, Dunkirk, and The Darkest Hour achieved a rare movie "triplet." More common, but equally uncanny, is when two movies "twin," a term for the phenomenon in which blatantly similar films come out within a short span of time, like when Antz and A Bug's Life, two animated films with essentially the same plot, premiered within a month of each other in the summer of 1998.