He served as military instructor in the
Chilean Army between 1895 and 1897. In 1900 he was sent to serve in the Schutztruppe in Kamerun, of which he became the commander in 1909. It was in this function that he directed the military operations against a Franco-British-Belgian
invasion of Kamerun, after the outbreak of the
First World War. By 1916, the situation was so desperate that Zimmermann and his troops had to flee to neutral Spanish
Río Muni, where they were interned and eventually sent to a detention center near
Zaragoza. After his return to Germany he served shortly in the
Reichswehr and retired in 1920 as Generalmajor. == See also ==