The Battle of the Ardennes, 20-25 August 1914 (First World War) was part of the larger Battle of the Frontiers of France. It was fought between two French and two German armies of roughly equal size – both sides committed eight Corps to the battle.
The two German armies (Fourth, under the Duke of Württemberg and Fifth under Prince Frederick William) formed the hinge of the great movement through Belgium. During the first few weeks of the war, these armies had remained largely in place, while the Fifth Army attacked the French frontier fortresses of Montmédy and Longwy. To the north the German First, Second and Third armies took part in the great advance across Belgium.
The French had two armies facing the Ardennes – the Third under General Pierre de Ruffey and the Fourth under General Fernande de Langle de Cary. Faced with the German advance through Belgium, General Joffre ordered these armies to advance north east through the Ardennes. The French did not expect to face any serious opposition during their advance. A prolonged cavalry sweep of the Ardennes (6-15 August), performed by Sordet’s Cavalry Corps, had found no Germans. In contrast, German aircraft had noticed French troops moving north and although these troops were actually from the French Fifth Army, the Germans had come to the conclusion that the French were about to advance into the Ardennes.
On 22 August the French advance ran unto the Germans. The advance guard of the Third Army was hit by a German artillery bombardment and shattered. The Third Army, with a gap in its centre, was forced to stop and fight just to maintain its position.
The Fourth Army also suffered heavy losses on 22 August. This army contained the Colonial Corps, the main regular element of the French army. These professional troops advanced ahead of their support until they were fighting alone. They then made a series of determined attacks on German positions that cost them dear. On 22 August the 3rd Colonial Division lost 11,000 of its 15,000 men.
With their offensive stalled and key elements of both armies badly mauled the French were forced to withdraw. On 24 August both armies pulled back to the line of the Meuse. The Third Army took up positions around Verdun, while the Fourth moved to Stenay and Sedan, before eventually being forced to pull back further south in a retreat that would only end with the Battle of the Marne.