August von Mackensen Anton Ludwig August von Mackensen ( 6 December 1849 – 8 November 1945 ) , born August Mackensen , was a German soldier and field marshal . He commanded with success during the First World War and became one of the German Empire ' s most prominent military leaders . After the Armistice , Mackensen was interned for a year . He retired from the army in 1920 and was made a Prussia n state councillor in 1933 by Hermann Göring . Mackensen , a nationalist rather than a National Socialist , frequently appeared at Nazi functions wearing his imperial cavalry uniform and became a major symbol of the integration of the Second and Third Reich . Early years . Mackensen was born in Haus Leipnitz , near the village of Dahlenberg in the Prussian Province of Saxony , to Louis and Marie Louise Mackensen . His father , an administrator of agricultural enterprises , sent him to a Realgymnasium in Halle in 1865 , with the apparent hope that Mackensen would follow him in his profession . Mackensen began his military service in 1869 as a volunteer with the Prussian 2nd Life Hussar Regiment ( " Leib - Husaren - Regiment Nr . 2 " ) . During the Franco - Prussian War he was promoted to second lieutenant and recommended for the Iron Cross , Second Class . He left service and studied at the Halle University , but formally returned to the German Army in 1873 , with his old regiment . Regarded as among the finest horsemen in the Empire , he was detached from normal duties to serve as a tutor of military history to the future Kaiser Wilhelm II , who would later send his own son to serve in Mackensen ' s regiment . Close relations between the emperor and Mackensen would continue for many years . In 1891 he joined the General Staff in Berlin , where he was heavily influenced by the new chief , Alfred von Schlieffen . From 17 June 1893 to 27 January 1898 , Mackensen commanded the 1st Life Hussar Regiment ( " Leib - Husaren - Regiment Nr . 1 " ) , to which he became " à la suite " when he left command and whose uniform he often wore as a general . He was ennobled on 27 January 1899 , becoming August von Mackensen . From 1901 to 1903 , he commanded the Life Hussar Brigade ( " Leib - Husaren - Brigade " ) , and from 1903 to 1908 he commanded the 36th Division in Danzig . When Schlieffen retired in 1906 Mackensen was regarded by some as a possible successor , but the job went to Helmuth von Moltke the Younger . In 1908 , Mackensen took command of the XVII Army Corps , and commanded this corps until shortly after the beginning of World War I . World War I . Already aged sixty - five at the beginning of World War I , Mackensen remained in command of XVII Army Corps as part of the Eighth Army , first under General Maximilian von Prittwitz and later General Paul von Hindenburg . Mackensen had his corps moving out on a twenty - five kilometer march to the Rominte River within fifty minutes of receiving its orders on the afternoon of August 19th , 1914 as the Imperial Russian Army invaded East Prussia . Soon after , Mackensen ' s corps fought in the battles of Gumbinnen and Tannenberg . On 2 November 1914 Mackensen took command of the Ninth Army from General von Hindenburg , who had been named Supreme Commander East ( " Oberbefehlshaber Ost " ) . On 27 November 1914 Mackensen was awarded the " Pour le Mérite " , Prussia ' s highest military order , for actions around Łódź and Warsaw . He commanded the Ninth Army until April 1915 , when he took command of the Eleventh Army and Army Group Kiev ( " Heeresgruppe Kiew " ) , seeing action in Galicia , and assisting in the capture of Przemyśl and Lemberg . He was awarded oak leaves to the " Pour le Mérite " on 3 June 1915 and promoted to field marshal on 22 June . After this campaign , he was awarded the Order of the Black Eagle , Prussia ' s highest - ranking order of knighthood . During this period , he also received numerous honours from other German states and Germany ' s allies , including the Grand Cross of the Military Max Joseph Order , the highest military honour of the Kingdom of Bavaria , on 4 June 1915 . Serbian campaign . In October 1915 , Mackensen , in command of the newly formed Army Group Mackensen ( " Heeresgruppe Mackensen " , which included the German 11th army , Austro - Hungarian 3rd army , and Bulgarian 1st army ) , led a renewed German - Austro - Hungarian - Bulgarian campaign against Serbia . The campaign finally crushed effective military resistance in Serbia but failed to destroy the Serbian army , which , though cut in half , managed to withdraw to Entente - held ports in Albania and , after recuperation and rearmament by the French , reentered fighting on the Macedonian front . During the fight for Belgrade , the troops of the Central Powers encountered a very stiff resistance , so Mackensen erected a monument to the Serbian soldiers who died defending Belgrade , saying , " We fought against an army that we have heard about only in fairy tales . " Romanian campaign . He followed this up in 1916 with a successful campaign against Romania ( under the overall command of General Erich von Falkenhayn ) . He was in command of a multi - national army of Bulgarians , Ottoman Turks , and Germans . Despite this , his offensives were very successful , breaking every army that faced his own . On 9 January 1917 , Mackensen was awarded the Grand Cross of the Iron Cross , becoming one of only five recipients of this honour in World War I . From 1917 on , Mackensen was the military governor of the parts of Romania ( mainly Wallachia ) controlled by the Central Powers . His last campaign was an attempt to destroy the Romanian Army , which had been reorganised after the Kerensky Offensive , and occupy the rest of the country ( the north - eastern part ) . But the attempt failed at the Battle of Mărăşeşti , both sides taking heavy losses , but with the Romanian army victorious . At the end of the war , he was captured by General Louis Franchet d ' Espèrey ' s Allied army in Hungary ( namely by the Serbian units ) and held as a military prisoner in Futog , until November 1919 . Post - war career . In 1920 , Mackensen retired from the army . Although standing in opposition to the newly established republican system , he avoided public campaigns . Around 1924 he changed his mind and began to use his image as war hero to support conservative , monarchic groups . He routinely appeared in his old Life Hussars uniform . He became very active in pro - military conservative organisations , particularly " Stahlhelm " and the Schlieffen Society . During the German elections of 1932 Mackensen supported Hindenburg over Adolf Hitler , but following the latter ' s accession to power Mackensen became a visible , if only symbolic , supporter of the Nazi regime . Mackensen ' s high - profile public visibility in his distinctive black Life Hussars uniform was recognized by the Hausser - Elastolin company which produced a 7 - cm figure for its line of Elastolin composition soldiers Mackensen ' s fame and familiar uniform gave rise to two separate Third Reich formations adopting black dress with " Totenkopf " badges : the " Panzerwaffe " , which claimed the tradition of the Imperial cavalry ; and Hitler ' s " Life Guards , " the SS . Although Mackensen appeared in his black uniform at some public events presented by the German government or the Nazi party , he objected to the killings of Generals Ferdinand von Bredow and Kurt von Schleicher during The Night of the Long Knives purge of July 1934 , and to atrocities committed during the fighting in Poland in September 1939 . By the early 1940s Hitler and Joseph Goebbels suspected Mackensen of disloyalty but could do nothing . Mackensen remained a committed monarchist and appeared in full uniform at Kaiser Wilhelm II ' s 1941 funeral ( Doorn , the Netherlands ) . Mackensen died at the age of 95 , his life having spanned the Kingdom of Prussia , the German Empire , the Weimar Republic , Nazi Germany , and post - war Allied occupation . Family . Mackensen married Dorothea von Horn ( 1854 – 1905 ) in November 1879 , they had five children : After the death of his first wife Mackensen married Leonie von der Osten ( 1878 – 1963 ) in 1908 . Citation . On 4 February 1940 , Mackensen wrote to Field Marshal Walther von Brauchitsch : " As a man becomes older , he has to watch carefully that age has not reduced his creativity . After reaching the age of 90 , I have decided not to involve myself any longer with matters that are not concerned with my private life . However , I am still the most senior German officer . Many turn to me , sometimes with wishes , but more often with their concerns . During these weeks our concern is with the spirit of our unique and successful Army . The concern results from the crimes committed in Poland , looting and murder that take place before the eyes of our troops , who appear unable to put an end to them . An apparent indifference has serious consequences for the morale of our soldiers and it is damaging to the esteem of our Army and our whole nation . I am sure that you are aware of these events and that you certainly condemn them . These lines intend to convey my daily growing concern at the reports that constantly reach me , and I have to ask you to take up this matter with the highest authority . The messages I receive are so numerous , many come from high ranking persons and from witnesses . As the most senior officer I cannot keep them to myself . In transmitting them to you , I fulfil my duty to the Army . The honour of the Army and the esteem in which it is held must not be jeopardised by the actions of hired subhumans and criminals . sieg heil " Honours . The University of Halle - Wittenberg appointed him to Honorary Doctor of Political Sciences and the Gdańsk University of Technology granted him the Dr . Ing Mackensen was Honorary Citizen of many cities , such as Danzig , Heilsberg , Buetow and Tarnovo . In 1915 , the newly formed rural community of Mackensen in Pomerania was named after him . In various cities , streets were named after him . The " Mackensenstrasse " in the Schöneberg district of Berlin was renamed " Else Lasker - Schüler - road " in 1998 based on the attribution of him as one of the " pioneers of National Socialism " .