The Hussars of the 12th Cavalry Brigade were attached to the 5th Cavalry Division, which was part of the First Cavalry Corps. It formed part of the German Third Army which carried out the attack on France and Belgium in August 1914 as part of the long-prepared Schlieffen Plan. Richthofen crossed the Meuse at Dinant, and his unit was involved in heavy action against the French VIII Cavalry Corps. It fought in Belgium at Namur on 23–24 August during the siege of the city and again at Saint-Quentin. The 5th Cavalry continued its drive into France after the Battle of the Frontiers, but was stopped at the First Battle of the Marne in September. In recognition for bravery in combat, Richthofen was awarded the Iron Cross Second Class () on 21 September 1914. The new combat environment of trench warfare greatly lessened the effectiveness of cavalry, so Richthofen's division was transferred to the Eastern Front, arriving in Poland in November 1915.