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The Most Important Battle in History

Dr. John Jr. Tierney, Jr. argues that the Battle of the Marne is the most important battle in world history.

What is the most important battle in history?

Many claim that the answer is too complicated, as it “depends” on what one defines as “important” and as “history.” Fair enough.

All this, however, only begs the question: what was the most important war in history? A significant battle in an obscure war has to be omitted. As does an obscure battle in a significant war. Thus, the first task is to identify the war and the battle will logically follow.

World War I

It is a consensus that World War I shaped modern history more than any other event. Not only did it cause its immediate successor, World War II, but it has directly or indirectly served as a background for practically everything that has occurred since: atomic/nuclear weapons, colonial wars (including Vietnam), the Cold War, the War on Terror and, for what’s it’s worth, all that can even be seen on the horizon.

The next question: why does the recent/present qualify as more “important” than previous wars? How about the Peloponnesian War (400 BC), the Battle of Hastings (1066), Spanish Armada (1588), Trafalgar (1805), Waterloo (1815), or even Gettysburg (1863)? They certainly influenced their own time periods, but we have no reason to insist that those times can be defined as more important than our times.

Here, we have to be somewhat “arbitrary,” i.e. modern times, with seven billion people and with global issues, rather than local/regional, must take precedence.

Conclusion: World War I.

Next question: what battle shaped that war more than any other? The one that started and defined it (Marne), the most horrific (Somme, Verdun tied), or the last (German Spring Offensive, 1918)?

Both the Somme and Verdun (1916) saw unprecedented casualties. On the first day of the Somme, July 1, the British Expeditionary Force, BEF, suffered 60,000 casualties, 20,000 dead. Until the battle’s end, the BEF charged into German lines a total of 93 more times. The Battle of the Somme ended on November 18! Verdun began on February 21 and lasted nearly the entire year, December 18, with over 200,000 dead and about 800,000 total casualties, French and German.

Losses in each of these tragedies were unprecedented in all history, but neither stopped the war, which went on for two more years.

The German Spring Offensive was expected to end the war, despite the presence of millions of American soldiers. It was not to be. Beginning on March 21, 1918, the offensive effectively ended with an Allied counterattack on August 8, declared a “black day” in German military history.

The American presence, after four years, was certainly decisive but occurred only at the end, June to November. That ended the war, but the great tragedy of the event, and its ultimate importance, began in 1914, and it is to the beginning that we seek an answer to the question.

The Battle of the Marne, September 5 to September 13, 1914, is the most important battle in world history.

The Battle of the Marne, September 5 to September 13, 1914, is the most important battle in world history.

The Marne

The selection of the first, rather than the last, battle of history’s greatest war lies in the implications of the occasion. Neither the duration nor the casualties are historic by themselves.

To appreciate this, we must go back somewhat to 1870, the Franco-Prussian War. An upstart Prussia, led by Otto von Bismarck, maneuvered France, led by Napoleon’s nephew Charles Louis Bonaparte, into a short but disastrous war that subsequently replaced France with Germany as Europe’s foremost military power. This conflict was settled almost immediately when the Prussian Army routed the French at Sedan, September 2, 1870 and after a long siege of Paris the French surrendered and the modern German nation-state was formed.

In 1914, the two were again at war, with both prepared for another “Sedan” to decide the end. By early September, German Commander Helmut von Moltke had his armies poised to invade Paris again, but another counterattack, led by the Military Governor of Paris, General Joseph Gallieni, opened up a gap in the German line. French and BEF troops began entering that gap on September 6, creating a wide divide in the German lines, and thus ending any threat to the French Capitol. The possibility of another “Sedan” had disappeared.

As the Battle of the Marne (the 314-mile-long river east and southeast of Paris) progressed, German armies began a retreat west and northwest of Paris. With both French and British armies in pursuit, the Germans headed toward the North Sea, a retreat that saw them trying to affect an envelopment of the Allied armies toward a possible encirclement of Paris. Each effort was repulsed, a march that came known as “the race to the sea.”

By the time both sides had reached the Sea, they had nowhere else to go and began replacing their rifles with shovels. As they dug deeper and longer, outlines of what soon would be called the “Western Front” began to emerge, a stretch of trench-lines that would eventually encompass the 500 miles between the North Sea and the Swiss border.

In his effort to strengthen his armies, General Gallieni initially “commandeered” the Paris taxi fleet, which he charged to transport the Paris Garrison to the front lines. With their meters still running, over 6,000 men were sent to the front, a fairly insignificant number, but a maneuver that became enshrined in French history as symbolic of national resolve (taxi companies were duly compensated for their service).

Why the Marne

By September 13, General von Moltke (who suffered a breakdown and was relieved) is said to have told the Kaiser, “Your Majesty. We have lost the war.”

But Moltke was only half-right. The Battle of the Marne guaranteed that neither army could either win or lose. “Home by Christmas” had now been replaced by a four-year-long strategic stalemate of defensive, barbwire and trench warfare, where millions of men would die in mud for a mile of territory. Where neither Paris nor Berlin would face occupation, but where a generation of Europe’s elite young men would disappear for a contest without a clear winner, only to do it all over again, with a new generation and newer, even more terrible weapons.

The Twentieth Century is the significance of the Battle of the Marne.


The Institute of World Politics is a graduate school of national security, intelligence, and international affairs, dedicated to developing leaders with a sound understanding of international realities and the ethical conduct of statecraft, based on knowledge and appreciation of the founding principles of the American political economy and the Western moral tradition.

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