Hans Hemmer was born on 26 June 1869 in
Munich,
Kingdom of Bavaria as the son of
Oberst (Colonel) Anton Hemmer and his wife Ida,
née Weißmann. After graduation from the humanistic
Gymnasium in
Regensburg, on 12 August 1888 Hemmer entered the Royal Bavarian 11th Infantry Regiment "Von der Tann" (
Königlich Bayerisches 11. Infanterie-Regiment „von der Tann“) as an officer candidate. On 7 July 1889, he was transferred to the Royal Bavarian 2nd Infantry Regiment "Crown Prince" (
Königlich Bayerisches 2. Infanterie Regiment „Kronprinz“) and on 6 March 1890 he was commissioned a
Sekondelieutenant. Hemmer served as a battalion adjutant in that regiment from 15 February 1893 to 1 June 1896, after which he was sent for 3 years of general staff training to the Bavarian
War Academy. Having been transferred to the
Eastern Front, Hemmer distinguished himself as chief of the general staff of the
South Army in
Galicia under General
Felix Graf von Bothmer, and was decorated with the Knight's Cross of the
Military Order of Max Joseph, Bavaria's highest military honor. After the
Armistice on November 11, he and
General der Infanterie Karl Ritter von Fasbender, who had assumed command of the 19th Army on 8 November, oversaw the withdrawal of the 19th Army back to German territory. ==Post-war service==