On the face of it, the World War II flick “Dunkirk’’ would not be expected to be the must-see summer season movie. The film, about the seaborne rescue of hundreds of thousands of Allied soldiers from capture or death at the hands of the German army, is not the usual light, fun summer movie. Yet, Christopher Nolan’s epic from Warner Bros. topped expectations, pulling in $50.5 million in its opening weekend in the United States, according to Box Office Mojo.

The movie, starring Tom Hardy and Mark Rylance, was estimated to make $40 million in its U.S. opening.

“Dunkirk’’ opened at 3,720 locations and was the top-grossing film for the weekend, ahead of the surprising “Girls Trip,’’ which grossed $30.4 million.

“Dunkirk’’ brought in $105.9 million worldwide, according to online box office data compiler Box Office Mojo. The opening weekend already places “Dunkirk’’ among the top 25 World War II motion pictures of all time, based on data from Box Office Mojo.

The film’s appeal was boosted by critical and viewer acclaim and possibly the fact that Nolan — known the “Batman’’ trilogy and “Inception’’ — insisted the movie be shown in high resolution.

“Dunkirk’’ has done well enough at the box office to break the top 25 highest-grossing motion pictures ever about World War II. It has a ways to go, however, before it breaks into the elite company of the top 10.

Click here to see the 25 top-grossing World War II movies.