The Imperial German Army in 1914 was actually an army of confederated German speaking countries that had formed after 1871. The Prussians, augmented by a number of minor states such as Hamburg and Anhalt, made up the bulk and provided some 19 Corps including the Guards, the I-IX, XIV-XVIII, XX, and XXI. Bavaria had three independent corps (I, II and III Bavarian Army Corps) as well as their own air force.
The Royal Saxon Army supplied two Corps, the XII and XIX. Würtemburg marshaled its forces into the XIII Army Corps. The Grand Duchy of Baden provided the lansers for the XIV Army Corps. Each corps had two divisions and each division had four infantry regiments organized in two, two regiment brigades.
As each of the states had their own regiments that were part of the larger national army, they carried two names. For instance, the 4th Regiment of the Royal Saxon Army was also the 103rd Regiment of the Imperial German Army.
Which explains the below:
“A portrait of a Saxon infantryman with the 4th Regiment Royal Saxon Army, 103 Infantry Regiment of the German Reich (Kgl. Sächs. 4. Infanterie-Regiment Nr.103), possibly taken in his garrison at Bautzen, Eastern Saxony, circa 1916. He wears the model 1907/10 Feldrock tunic with the belt buckle with the Saxon motto, ‘Providentiae Memor’ (Providence Remember), and is armed with a Gew. 98 mauser rifle fitted with a S98/05 bayonet. (Image courtesy of the Drake Goodman Collection, colorized by Benjamin Thomas.)”
