Broadly speaking, there are three types of movies about battles. All of them are at least loosely set during an actual battle and to some extent give the history of the battle. Many only focus on one side of the conflict—like Wake Island, Bataan or 1958’s Dunkirk–or 2017’s Dunkirk.
In his book Where Eagles Dared: The Filmgoer’s History of World War II, Howard Hughes (a Howard Hughes—not the Howard Hughes) writes, “The beginning of the sixties marked the emergence of the international war epic, part of a trend that saw cinema reacting to the threat posed by television” (x). These movies showed both Allied and Axis sides of the story, usually had actors speak in the languages of their characters (instead of accented English), and often tried to be historically accurate, but their economic model, generally speaking, was to wrap the historic parts of the story in layers and layers of stars and action.
There are a great number of movies about World War II battles that show both sides, but many don’t have the scope of The Longest Day and A Bridge Too Far in particular. Some might say The Bridge at Remagen, The Battle of the Bulge and Anzio are international war epics, but I wouldn’t. These are Battle movies, but they don’t have the scope and the German or Italian (or Japanese in 1975’s Midway) characters speak English.