Over 60 years have passed since D-Day—that most momentous operation of World War II—and yet it remains as vibrant and inspiring today as it was then, in 1944. The unity, focus, and overall coordination of the assault remain unsurpassed and its lessons a worthy topic for study and admiration.

In The D-Day Companion, a compilation of essays edited by Jane Penrose, 12 leading historians look at 13 different facets of the invasion, from Hitler’s buildup of the Atlantic Wall to the Allies’ incredible efforts at deception and counterintelligence. The essays range from the tactical to the human and convey lessons in ways that are often easily understood.

In Chapter 6, for example, by Professor Williamson Murray, the basic advantage accrued by Allied air superiority is laid out in simple detail. Readers learn how the destruction of transportation networks in France denied Germany critical re-supply routes on D-Day; and how the ongoing bombing of Germany tied down countless German soldiers that could have been better employed on the front lines.

In Chapter 7, Dr. Andrew Gordon discusses the massive sea component of D-Day, known as Operation Neptune, and reveals the important Allied advantage in using mobile seaports, or mulberries. By not tying their destination to a pre-established port, the Allies were able to be more selective in their landing point—and thus maintain the element of surprise, one of the most critical factors in the success of the invasion.

Not everything went the way of the Allies, however, on D-Day, as Professor Allan R. Millett reveals in Chapter 9. Airborne troops of the 82^nd and 101^st Divisions landed in flooded river valleys, often miles from their landing zones, with unfortunately high losses in gear and life. The drops were dominated by confusion, and as Millett says, “Only the fighting heart of younger officers and sturdy troops saved the operation.”