General Ludwig von Falkenhausen was the German commander during the battle of Vimy Ridge, one of the few clear-cut Allied victories of 1917. Von Falkenhausen entered the Prussian army in 1856 as a cadet and fought in the Seven Weeks War (June-August 1866), where Prussia established her supremacy within Germany, and the Franco-Prussian War of 1870-71, which ended with the formation of the unified German Empire.
By 1914 Falkenhausen had retired, but he was called back to the colours and given command of the Ersatz Corps of the Sixth Army on the Western Front. During the Race to the Sea Falkenhausen's corps was one of the few units that remained in Lorraine as the main German armies rushed north. Falkenhausen had command of a slightly larger force, Army Detachment Falkenhausen. The Sixth Army itself moved north, but Falkenhausen remained in the south into 1916, fighting in Lorraine. He was awarded the Pour le Merite on 23 August 1915 for his efforts on the Lorraine front.
In April 1916 Falkenhausen was given command of the coastal defences near Hamburg. At the same time he was awarded the Oak Leaves to his Pour le Merite (15 April 1916).
On 28 August 1916 Crown Prince Rupprecht of Bavaria was promoted from command of the Sixth Army to command of the Army Group on the Somme. Falkenhausen was moved back from the coast and given command of the Sixth Army.
This meant that Falkenhausen was in overall command when the British attacked at Arras in 1917, and in particular for the famous Canadian attack on Vimy Ridge. At first glance the ridge was a very strong defensive position, but the topography didn't really suit the current German tactics of defence in depth. Ideally the German second line, where the main battle was to be fought, would have been a few thousand meters behind the lightly held front line, but the ground fell away steeply east of the ridge, so any second line placed at the standard distance would have been overlooked from the front line on the top of the ridge. As a result the Germans decided to concentrate most of their defences in an unusually strong first line. The third line of defence was made up of counter-attack units, which were meant to be used to attack enemy troops caught up in the second line. Despite the absence of that second line at Vimy Ridge Von Falkenhausen decided to keep his counterattack units at the usual distance behind the first line, so at best they would only be able to enter the battle just over three hours after being called into action. In normal circumstances this probably wouldn't have mattered, as the strong front lines could be expected to hold any attack for several days.
The Germans were thus entirely caught out when the Allies attacked in April 1917. The southern part of Vimy Ridge was captured in the initial well-planned assault, and the German reserve divisions were too far away to mount a successful counterattack. Although the Allies were unable to make much progress in the days after the initial attack, the Germans were eventually forced to retreat to their next line of defences, leaving Vimy Ridge in Allied hands.
In the aftermath of this failure Ludendorff removed Falkenhausen from command of the Sixth Army. He was appointed Governor-General of Belgium in May 1917 and held that post for the rest of the war. He retired in 1918 and died in 1936.