Paul von Hindenburg
Paul von Hindenburg (1847-1934) German Field Marshal in WWI, with great popularity although moderate military skills, more a figurehead with the operational control under Erich Ludendorff, and Wilhelm Groener managing logistics. Nevertheless, he became Commander-in-Chief. Groener, acting for him, told Wilhelm II he had to abdicate. He later became President of Germany (1925-1934), and Adolf Hitler was only able to gain control after his death, under arrangements agreed to by Hindenburg.
In his earlier military career, he served in the Austro-Prussian War (1866) and Franco-Prussian War (1870-71) retiring in 1911. As a commander, he was best known for the victory over Russia at the Battle of Tannenberg, which actually was controlled by Ludendorff.
He replaced Friedrich Ebert as President after the latter's death. His reputation, even then, was as a monarchist.