The Fifth Army was formed in 1914 as part of Austro-Hungarian mobilisation following its declaration of war on Serbia and Russia.

[1] The Fifth Army comprised the VIII Corps from Prague, under with two infantry divisions (9th K.u.k.

and 21st Landwehr), and the XIII Corps from Zagreb (Agram) in Croatia with two infantry divisions (36th K.u.k.

[1] The Fifth Army represented approximately 93,000 rifles and included a large proportion of South Slavs from the Empire.

[2] Between August and December 1914, it fought in the First Serbian Campaign and suffered such enormous casualties fighting the Serbian Army that it was disbanded on 27 December 1914 and the commander of the Balkanstreitkräfte was forced to resign.