In 1866 the active army, on a war footing, comprised nine army corps, and aggregated 335,000 men. Each corps consisted of twenty-four battalions of infantry, sixteen batteries of artillery, twenty-four squadrons of cavalry, one battalion of rifles, one battalion of engineers, an engineer train, and a military train conveying ammunition and subsistence, quartermaster’s and hospital supplies. Each infantry battalion numbered 1,000 men. Three battalions formed a regiment, two regiments a brigade, and two brigades a division. Each battery contained six guns. Four batteries were assigned to each infantry division, two batteries of horse artillery were attached to the cavalry division, and four batteries of field and two of horse artillery constituted the reserve artillery of each corps. Each squadron of cavalry numbered about 140 sabres. Four squadrons composed a regiment, two regiments a brigade, two brigades a division. A regiment of cavalry was attached to each infantry division. Each corps numbered about 31,000 combatants, except the Guards, which numbered 36,000--having four additional battalions and eight additional squadrons. During the campaign under consideration, the cavalry of an army corps consisted of only one regiment to each division of infantry; the cavalry division being taken from each corps, and merged into the corps of reserve cavalry. The depot troops consisted of a battalion for each regiment of infantry, a squadron for each regiment of cavalry, an _abtheilung_ [3 or 4 batteries] for the artillery of each corps, and a company for each rifle battalion, engineer battalion and train battalion. The army in the field was constantly kept up to a full war strength by men drawn from the depots. The fortresses were garrisoned by Landwehr; and on troops of the same class devolved the duty of pushing forward to occupy invaded territory, and to relieve the active army from the necessity of leaving detachments to guard its communications. This is a brief outline of the organization that enabled a nation of less than 20,000,000 people eventually to bring 600,000 soldiers upon the theatre of war, and to place a quarter of a million of them upon the decisive field of Königgrätz.