By Mike Bennighof, Ph.D.
During the 1700s, European armies grew enormously
in size. The Seven Years’ War of 1756
– 1763 heightened the trend, and by
the end of the Napoleonic Wars field armies
had become enormous. Forces of 100,000 or
even more, unheard of a century before, were
not at all unusual by 1815.
The French army introduced the concept of
a corps d’armee, a body of infantry,
cavalry and artillery plus essential services.
The corps could fight alone or in cooperation
with other corps, and included all necessary
combat and administrative elements. By the
end of the Napoleonic wears, all participants
had organized their troops into corps, usually
made up of varying numbers of divisions and
During the years after 1815, some nations
kept their corps structure in place during
peacetime, using them to administer recruiting,
training and other non-combat functions. This
would speed mobilization and keep the staffs
employed. The size and composition of corps
also became regularized, with each usually
having the same number and types of subordinate
By the middle of the 19th century, an army
corps had become defined as the number of
troops that could be deployed from a single
road in less than two hours: roughly 20,000
men. That rule of thumb had been badly exceeded
as extra troops were added: cavalry, engineers,
artillerymen, light infantry, medical services,
supply columns and more.
The Prussian corps organization used in
the 1866 Austro-Prussian War had been introduced
as part of War Minister Albrecht von Roon’s
reforms starting in 1860. In 1859, the Prussian
Army mobilized its four army corps for war
on the side of Austria against France. The
mobilization found many troops untrained,
officers of poor quality and supply services
either insufficient or non-existent.
It also showed just how unwieldy the army’s
corps organization would prove in action.
The German Confederation, which included both
Austria and Prussia along with 36 other german
states, had adopted a corps of four divisions.
Each division consisted in turn of two or
three brigades, each brigade with two regiments
of two battalions each plus one of light infantry.
All told, a German division would go to war
with 10 or 15 battalions, a corps with between
40 and 60.
Roon rationalized this organization; in
battle, he believed, a general was most efficient
with fewer maneuver elements to command. A
new-model Prussian infantry corps would have
two divisions. Each division in turn had two
brigades, and each of them had two regiments.
The regiments would be larger, with three
battalions rather than the former two, as
a regimental colonel was expected to control
all three by line of sight.
A brigade commander only had to control
the two regiments under his command. At the
division level, things got more complex. The
division controlled two brigades, plus an
artillery detachment of four six-gun batteries.
These would usually be parceled out to the
brigades in action. During peacetime the division
was responsible for either a pioneer battalion
or a light infantry battalion; during wartime
these would be held in the corps reserve.
The corps controlled the two infantry divisions,
plus attachments of artillery and cavalry.
This varied from four to seven batteries (six
guns each) and two to five cavalry regiments.
Austria also reformed its corps organization
in 1860, based on the lessons of the 1859
war. An Austrian corps had included two or
three divisions, each in turn of two or three
five-battalion brigades. Each brigade included
the four field battalions of a single regiment
plus a light infantry battalion: usually jägers
but in a few cases grenzers (Croatian border
troops) or volunteer student battalions.
Austrian generals performed poorly in the
1859 war, and the reform commission appointed
after the war recommended using fewer of them.
In particular, it pointed out that the small
brigades made regimental colonels superfluous.
A peacetime regiment had contained four field
battalions and a grenadier battalion; now
they would have three field battalions, a
fourth reserve battalion and in wartime a
fifth training battalion. Two of these three-battalion
regiments would be grouped in a brigade along
with a light infantry battalion and an eight-gun
artillery battery. It was a powerful and flexible
organization, led by a major general (Austria
did not have a “brigadier general”
rank and this was the imperial army’s
equivalent). The larger brigades required
fewer light infantry battalions, allowing
the role to be filled exclusively by jägers.
The organization became less flexible at
the larger echelons. An Austrian corps included
four infantry brigades, a cavalry regiment
and a brigade-sized artillery reserve as well
as engineer, supply and medical units. The
new arrangement required fewer general officers,
which had been the goal. But handling six
maneuver elements proved beyond the capability
of most Austrian corps staffs in 1866, and
the intermediate stage of division headquarters
gave Austria’s Prussian opponents a
decided advantage in flexibility and reaction
speed. Though the Prussian staff was undoubtedly
better organized and more efficient than their
Austrian counterparts, their organization
also gave them a lighter workload.
of 1866: Frontier Battles the units are infantry brigades,
cavalry regiments and artillery batteries,
but players maneuver their units by corps.
The corps are activated by the army command,
or through the initiative of the corps commander.
The Prussians generally activate in a much
more predictable fashion, and can get all
of their units into action thanks to the division
commanders. An Austrian corps is much more
difficult to handle and often only gets into
action piece by piece.
here to order Battles of 1866: Frontier Battles now.