Generaloberst, roughly translated as "Colonel General", was the second-highest general officer rank in the German Army and for a short period (1915–1918) in the Austro-Hungarian Imperial and Royal Army.
The position of “Colonel General” was already known from the 16th century, where it referred to the officer of the Holy Roman Empire of the German Nation in command of the infantry. In this context it is older than the single term “general”. The rank was re-introduced in 1854 with the Prussian Army for Wilhelm Prince of Prussia because members of the royal family were not traditionally appointed Generalfeldmarschall. It was introduced for Army of Saxony in 1889, for the Bavarian Army in 1911 and for the Army of Württemberg in 1913. The Imperial German Army also used this rank.
In the Austro-Hungarian Imperial and Royal Army (k. u. k. Armee), due to other organizational circumstances, such a rank did not originally exist for generals. Here the (full) general (of the cavalry, the infantry or Feldzeugmeister) was the highest regular rank, which was initially associated with the leadership of corps, later armies or army groups. Above that there was only the rare rank of field marshal, of which there was no active rank at the outbreak of the First World War. This soon led to complications. When the Austro-Hungarian army had to cooperate with the army of the German Empire on the Eastern Front during the WWI, the lack of a rank became noticeable. There were disputes over jurisdiction between German and Austrian departments, which ultimately led to the fact that in the Austro-Hungarian Empire, too, the rank of Colonel General was introduced in the army. In September/October 1914, the newly formed German 9th Army under General of Artillery Richard von Schubert was supposed to support the Austrian front. The Austro-Hungarian army high command demanded that the German troops be given their leadership, i.e. to be subordinate to that of General of the Infantry Franz Conrad von Hötzendorf (der). The nominal commander in chief of the Austro-Hungarian armed forces, Friedrich von Österreich-Teschen, was also a General of the Infantry. Since the German authorities were reluctant to place their troops under Austrian command, Paul von Hindenburg was simply appointed commander-in-chief of the 9th Army instead of General von Schubert. Von Hindenburg was Colonel General and therefore superior in rank to both the head of the k.u.k. General Staff as well as to the k.u.k. commander-in-chief. Citing this fact, the Supreme Army Command (OHL) ultimately rejected the allegations.
The designated commander-in-chief of the new Southwest Front, Archduke Eugen of Austria-Teschen (de), was himself only a full general and ranked in seniority even behind the older generals under his command. A promotion to field marshal was not an option because that would have put him on the same level as the supreme commander of the Austro-Hungarian Armed Forces, who had held this rank since December 1914. Without further ado, the Archduke was appointed the first Colonel General in the history of the Austro-Hungarian Empire on 22 May 1915. A month later, on 23 June 1915, Chief of General Staff Conrad von Hötzendorf was also elevated to this rank.
The Reichswehr and the Wehrmacht (Army and Luftwaffe) also had this rank as well as the East German National People's Army (Volksarmee) and in their respective police services (Volkspolizei). The rank was equal to a four-star full general. The rank was equivalent to a Generaladmiral in the Kriegsmarine until 1945 or to a Fleet Admiral (Flottenadmiral) in the East German Volksmarine until 1990. It was the highest ordinary military rank and the highest military rank awarded in peacetime; the higher rank of General Field Marshal was awarded only in wartime by the head of state. In general, a Generaloberst had the same privileges as a Generalfeldmarschall, that is why sometimes the rank "Colonel General in the rank of General Field Marshal" (Generaloberst mit dem Rang als Generalfeldmarschall) was given. A SS-Oberst-Gruppenführer (SS ranks) was also Generaloberst of the Waffen-SS with SS-Oberst-Gruppenführer Kurt Daluege (de) becoming the only Generaloberst of the police in 1942.