He joined the Infantry Regiment No. 74 of the Prussian Army as an ensign from the Cadet Corps , became a Second Lieutenant in 1873 and served as a battalion adjutant from 1878 to 1883. In 1883 Schaer became a prime lieutenant , in 1889 a captain and as such a company commander . In 1896 he was promoted to major . On March 22, 1897, he was transferred as an aggregated major to the 4th Hanoverian Infantry Regiment No. 164 , in 1898 as a battalion commander in the 7th Baden Infantry Regiment No. 142 , where he was promoted to lieutenant colonel in 1903 . In 1903 Schaer was transferred to the Infantry Regiment "von Wittich" (3rd Kurhessisches) No. 83 and in 1906 was appointed commander of the 8th East Prussian Infantry Regiment No. 45 while being promoted to colonel . On April 20, 1910, he took command of the 35th Infantry Brigade in Flensburg while being promoted to Major General . In April 1912 he was at his request, with presentation of the character as a lieutenant general for disposition made.
He spent his retirement in Hanover.
- Zachariae: List of officers of the 4th Hanoverian Infantry Regiment No. 164, formerly the 2nd Hanoverian Infantry Regiment Calenberg. ES Mittler & Sohn . Berlin 1913, p. 6f.
- Dermot Bradley (ed.), Günter Wegner: Occupation of the German Army 1815-1939. Volume 1: The higher command posts 1815–1939. Biblio Publishing House. Osnabrück 1990. ISBN 3-7648-1780-1 . P. 395.
|ALTERNATIVE NAMES||Schaer, Rudolf Ernst David Adolf (full name)|
|BRIEF DESCRIPTION||Prussian officer, most recently lieutenant general|
|DATE OF BIRTH||October 6, 1853|
|PLACE OF BIRTH||Stocken (Hanover)|
|DATE OF DEATH||June 29, 1927|