he left its command on 27 January 1898 and so he often wore the distinctive death's head uniform thereafter. Mackensen was surprised by his next posting, as adjutant to Wilhelm II because he was the first commoner to hold that position. For the next three-and-a-half years, he shadowed the Kaiser and met the high and mighty of Germany, the rest of Europe and the Middle East. His sons shared gymnastics classes with the Kaiser's. Mackensen was ennobled on the Kaiser's 40th birthday, 27 January 1899, and became August von Mackensen. Next, he received the command of the newly-created Life Hussar Brigade (Leib-Husaren-Brigade) from 1901 to 1903, and from 1903 to 1908, he commanded the 36th Division in Danzig. His wife died in 1905, and two years later, he married Leonie von der Osten, who was 22 years old. When Schlieffen retired in 1906, Mackensen was considered as a possible successor, but the position went to Helmuth von Moltke the Younger. In 1908, Mackensen was given command of the XVII Army Corps, headquartered in Danzig. The Crown Prince was placed under his command, and the Kaiser asked Mackensen to keep an eye on the young man and to teach him to ride properly. First World War Eastern Front Already aged 65 at the outbreak of war in 1914, Mackensen's XVII Army Corps became part of the German Eighth Army in East Prussia, under General Maximilian von Prittwitz and, 21 days later, under General Paul von Hindenburg. Mackensen had his corps moving out on a 25 km march to the Rominte River within fifty minutes of receiving his orders on the afternoon of 19 August 1914, after the Imperial Russian Army had invaded East Prussia. He led the XVII Corps in the battles of Gumbinnen, Tannenberg and the First Battle of the Masurian Lakes, which drove the invading Russians out of most of East Prussia. On 2 November 1914, Mackensen took over command of the Ninth Army from Hindenburg, who became Supreme Commander East (Oberbefehlshaber Ost). On 27 November 1914, Mackensen was awarded the Pour le Mérite, Prussia's highest military order, for successful battles around Warsaw and Łódź. By April 1915, the Russians had conquered much of western Galicia and were pushing toward Hungary. In response to the desperate pleas, German Chief of Staff Erich von Falkenhayn agreed to an offensive against the Russian flank by an Austro-German army under a German