Nikolaus von Rauch was born in Berlin. Following his family's tradition he entered the Prussian Army in 1870. He served in the
Franco-Prussian War in which he was promoted to Second-Leutnant and awarded the
Iron Cross (second class). Later he became adjutant of the 15th Cavalry Brigade and then of the
11th Division in Breslau. In 1893 Rauch was a squadron commander in the
16th (2nd Hannover) Dragoon Regiment in
Lüneburg. On April 4, 1899, Rauch became the commander of the
5th (Pomeranian) Hussar Regiment. He was part of Prussia's military delegation to the funeral of
Queen Victoria in 1901. By March 1902 Rauch had been promoted to Oberst. From 1904 until his death he commanded the 29th Cavalry Brigade. He died in
Stolp in Pomerania.