Fahrmbacher attended the artillery and engineering school from October 1911 to the end of June 1912, and on 25 January 1914, he was appointed adjutant of his regiment.

[1] Fahrmbacher was promoted to captain on 22 March 1918, and held that rank until the Armistice brought hostilities to a close.

[2] In May and June 1944, during Operation Overlord, Fahrmbacher temporarily led the LXXXIV Corps opposing the US forces in the Cotentin Peninsula.

[4] On 31 July 1944, with US forces breaking out into Brittany after Operation Cobra, Fahrmbacher was ordered to send all his mobile troops to hold the Pontaubault bridge.

[6] On 9 August, the US 4th Armored Division, led by Major General John S. Wood, began probing Lorient's defenses, but reported that they were too strong to be quickly captured.

[6] Fahrmbacher's successful defense of the Lorient fortress, which included the nearby Quiberon peninsula, prevented the implementation of Operation Chastity a plan to develop an artificial port in Quiberon Bay to supply the Twelfth United States Army Group.

[10] Fahrmbacher's last radio message to Reichspräsident Karl Dönitz on the afternoon of the surrender, was "Wish to sign off with my steadfast and unbeaten men.

[9] Upon Germany's surrender in 1945, Fahrmbacher was interned in France until 1950, during which time he wrote an appreciation of the Battle of Brittany for the Foreign Military Studies Branch of the US Army.

[14] Whilst in Egypt, Fahrmbacher, who was attempting to remodel the Egyptian Army with the goal of making it capable of performing large scale operations, was the subject of an assassination plot by the Israeli secret service, Mossad.