The Surprising History of the First Army

Military unit designations have gotten complicated with all the reorganizations and national variations flying around. As someone who’s studied army organizational history across multiple countries, I learned everything there is to know about the various formations called “First Army.” Today, I will share it all with you.

The term “First Army” isn’t unique to any single nation – multiple countries have designated field armies with this designation, each with distinct histories and ages. Understanding which “First Army” we’re discussing matters for answering when it was established.

The U.S. First Army: Over a Century Old

Probably should have led with this section, honestly. The United States First Army was established on August 10, 1918, making it over 105 years old. General John J. Pershing commanded it as the first American field army to fight in Europe during World War I. The Meuse-Argonne Offensive remains one of the largest operations in American military history, and First Army was at the center of it. That’s what makes this command so historically significant – it marked America’s emergence as a major military power.

The French First Army

France’s First Army dates to 1914, established at the outbreak of World War I under General Auguste Dubail. This makes it slightly older than its American counterpart – about 109 years old. The French First Army fought in the Battle of the Frontiers and remained active throughout both World Wars. Under General Jean de Lattre de Tassigny during World War II, it played a crucial role in liberating France from German occupation.

The British First Army

Britain’s First Army was a World War II formation, established in 1942 for Operation Torch – the Allied invasion of North Africa. Under Lieutenant-General Kenneth Anderson, it combined British, American, and French forces. This makes the British First Army about 81 years old, though it was disbanded after the war and doesn’t exist as an active formation today.

The German First Army

Germany’s First Army during World War II was established in 1939 under General Erwin von Witzleben. It participated in the invasions of Poland and France before being disbanded at the war’s end. Unlike American and French formations, the German First Army existed only during the war years – about six years total.

Why Ages Vary So Much

The dramatic differences in age reflect how different nations structure and maintain their military establishments. The U.S. and French First Armies maintained organizational continuity through multiple conflicts and peacetime periods. British and German formations were created for specific conflicts and dissolved when no longer needed. Each approach reflects different military philosophies and strategic requirements.

When someone asks “how old is First Army,” the answer depends entirely on which nation’s formation they mean. The designation exists across multiple military traditions, each with its own story of formation, combat service, and organizational evolution.