[2] The 1st Army was put under the command of General of the Cavalry Viktor Dankl von Krasnik and was composed of the I, V, and X Corps, originating from Kraków, Presburg and Przemyśl, respectively.

It was the transferred to the Bug river region and was part of Army Group Linsingen, under the overall command of August von Mackensen, but saw little action until the end of the Russian Great Retreat, at which point the front lines became static.

Romania also entered the war on that month, and the reformed 1st Army under Straussenburg managed to hold off a Romanian assault in Transylvania on 28 August, despite its numerical inferiority.

It continued to fight alongside the German 9th Army, as well as Bulgarian and Ottoman troops, over the next several months as the Central Powers entered Romania proper and occupied a large portion of it.

When the archduke became Emperor Karl I of Austria-Hungary in November, he assigned Straussenburg to replace Franz Conrad von Hötzendorf as chief of the general staff.

[8] Austro-Hungarian casualties were extremely high on the Eastern Front, and the casualty-struck 1st Army had to be disbanded on 15 April 1918, as conclusion of the peace treaty with Romania was imminent.