D arkest Hour, Joe Wright’s recent film, vividly describes the closing days of May 1940, when Adolf Hitler’s blitzkrieg swept over western Europe. In Britain, despite overwhelming odds, Winston Churchill convinced his country to fight on.

It is an excellent film — both historically accurate and dramatically taut. And Gary Oldman’s portrayal of Churchill far exceeds many of those we’ve seen in recent years. But the nature of the film means that viewers necessarily miss out on fascinating background and details.

Happily, there are many good books on those frightening few days that offer a broader picture than the film. If you liked the movie and want to learn more, here are three of the best:

Martin Gilbert, Winston S. Churchill, vol. VI, Finest Hour 1939-1941

(Hillsdale College Press, 2011, 1308 pages; http://amzn.to/2hBExwT)

This is a whacking big book, yet not expensive. It’s the key volume of Churchill’s enormous Official Biography. It puts you at his shoulder day by day in May 1940, as France falls and Britain is left alone. Part two of the volume, also called “Darkest Hour,” is easily the most memorable section, walking you through a shocking a catalogue of disaster and the constant barrage of setbacks and challenges Churchill faced.

John Lukacs: Five Days in London, May 1940

(Yale University Press, 2001, 236 pages; http://amzn.to/2hDwL5P)

Unlike Gilbert’s tome, this short book can be read in a few evenings. It focuses strictly on May 23-28, 1940. The author provides a rich account of Churchill’s achievement: changing opinions, dominating events. Lukacs, an emigrant from Hungary in 1956, has a fascinating perspective on how the decisions made over the course of those days shaped the political aftermath of World War II on the Continent. More than most, he understood firsthand the nature of Marxism. Yet he shows why Nazism, in 1940, was the greater threat. Hitler, he writes, was “the greatest revolutionary of the 20th century.” His triumph would have led to what Churchill called “a new dark age,” protracted by “perverted science.” Lukacs envisions a world of atomic bombs and ICBMs held by a victorious Third Reich. Alone among the leaders of 1940, Churchill saw that world.

David Owen, Cabinet’s Finest Hour: The Hidden Agenda of May 1940

(Haus Publishing, 2017, 320 pages, http://amzn.to/2krA3wJ)

David Own, British foreign secretary in the late 1970s, uses his unique insider’s experience of cabinet government to discuss Churchill’s cabinet, focusing in on individual members’ actions and attitudes toward a truce with Germany. Historian Andrew Roberts calls this book “masterly… the greatest moment for Cabinet government and collaborative politics supported by the key contemporaneous documents. An exciting, thought-provoking read, with profound contemporary as well as historical relevance.”

Mr. Langworth is Senior Fellow for the Hillsdale College Churchill Project. His latest book is WinstonChurchill, Myth and Reality.