At the beginning of the Great War the armies of the major belligerents were all organized in roughly the same manner. First came the numbered field armies, consisting of a variable number of corps. The German Army in the west, for example, was organized into seven field armies, each controlling two to four corps depending on the task allotted to them. The corps was the basic tactical formation; it typically consisted of two infantry divisions plus various corps troops. These latter usually included a medium artillery regiment, a cavalry brigade, a pioneer (combat engineer) battalion, and various supply columns. The total strength of a corps was usually 50,000 to 75,000 men. Cavalry corps were similar but substantially smaller.
Except for the British Army, infantry divisions were “square divisions,” so called because they embodied two brigades, each of two infantry regiments, each regiment with three or four battalions. The infantry divisions of the British Army, which did not recognize the regiment as a tactical echelon of command, were “triangular” with three brigades of four battalions each. The division artillery usually consisted of a brigade of two regiments with a total of 48 to 54 light field guns. Divisions also included a reconnaissance element — usually a cavalry squadron or regiment — a combat engineer unit and the division trains (supply and ammunition columns). Though a few motor vehicles were to be found, most transport was horse drawn. The total strength of a 1914 infantry division was 16,000 to 20,000 men, depending on nationality. Cavalry divisions had a similar organization but a much lower strength: usually 8,000–10,000 men and 12 to 24 guns.
The accompanying graphic depicts the organization of an active infantry division of the German Army in 1914. In most respects it was similar to French and Russian infantry divisions but its artillery brigade included one battalion of 105mm howitzers. These weapons were capable of high-trajectory fire, making them far more effective against masked targets and entrenched troops than the flat-trajectory light field guns that made up the bulk of all armies’ divisional artillery. This was to give the Germans a considerable initial advantage when the fighting congealed into trench warfare. (The small British Army shared in this advantage; its infantry divisions, initially four in number, also had a howitzer battalion.)
Field armies and corps sometimes has aviation squadrons attached. The aircraft were unarmed, being intended for reconnaissance only. Though many commanders doubted its value, in the 1914 campaigns the airplane proved itself invaluable, being much more effective than cavalry in the reconnaissance role.
The field armies of the belligerents embodied the divisions of the active army plus the first-line reserve divisions. The former, consisting of long-service professional soldiers and the current intake of conscripts, were maintained at “peacetime” strength; on mobilization they would take in sufficient reservists to bring all their units up to “wartime” strength. For example, the peacetime strength of a German infantry company was 150 men and its wartime strength was 270 men. The first-line reserve divisions, maintained as cadres only, were brought up to war strength on mobilization by absorbing the bulk of the most recently trained reservists. In most cases the first-line reserve divisions were slightly smaller than the active divisions, with fewer men and weapons. A first-line reserve infantry division of the German Army, for example, had only one artillery regiment with 36 light field guns.
Older reservists formed the second-line reserve units: territorial or Landwehr battalions and brigades for such duties as protecting lines of communication, guarding prisoners, garrisoning fortresses and the like. Usually they were armed with older weapons that had been superseded in the field army. In 1914, however, these reserve units often found themselves pressed into front-line service
Once again, however, the British Army constituted an exception to the rule. As a small all-volunteer force its reserve, consisting of men who’d completed their service with the colors, was only sufficient to bring the home-based part of the Regular Army (six infantry divisions and one cavalry division) up to wartime strength. The Territorial Army, somewhat analogous to the US National Guard, was a part-time volunteer force whose members bore no obligation for foreign service, though the great majority did volunteer to serve abroad. In 1914 the Territorial Army embodied some fourteen divisions, all understrength, inadequately trained and lacking sufficient modern weapons. It was to be many months before the first of them were ready for active service at the front.
The weapons in the hands of the soldiers of 1914 were few and basic: the pistol, the rifle and bayonet, the machine gun and, for cavalry, the saber and lance. Machine guns were usually grouped in regimental machine gun companies of 6–12 weapons. Division artillery consisted mostly of light field guns with a caliber of 75mm to 80mm. As noted above, only the active German infantry divisions possessed significant numbers of 105mm field howitzers capable of high-trajectory fire. Medium and heavy field artillery, such as it was, was controlled by the corps and armies, the Germans being somewhat better off than the others in this category of weaponry. In 1914 large numbers of heavy guns and howitzers permanently installed in fortresses were hurriedly dismounted and pressed into field service when the importance of heavy field artillery was realized.
The uniforms of the soldiers of 1914 present a varied picture. The British, the Russians and the Germans had already replaced the brightly colored uniforms of past times with khaki (for the first two) and gray-green (for the Germans) field uniforms. The Austro-Hungarian Army had done likewise, though its new blue-gray field uniform had been adopted with an eye to war on the mountainous frontier with Italy and proved rather too conspicuous for the Eastern Front. Only the French Army went to war in its traditional, highly visible, dark blue coats and madder-red trousers — not the least costly of the many mistakes it made in 1914. No army provided its soldiers with steel helmets.
Though such weapons were under development in the years leading up to 1914, no army as yet possessed the submachine guns, light machine guns, mortars, grenade launchers, etc. that would be in widespread use by 1918. Even so the firepower of an infantry battalion, particularly on defense, was orders of magnitude greater than that of its 1815 ancestor. Bolt-action magazine rifles like the British Short Magazine Lee Enfield (SMLE) were capable of delivering eight or ten aimed shots per minute with an effective range up to 1,000 yards. Supplemented by machine guns and supported by artillery, a 1914 infantry battalion in defensive positions was capable of stopping an attacking force many times its own size.
Most armies championed the tactical offensive, holding that a rapid, audacious attack could overcome any defense. Hence the emphasis, for example in the French Army, on the importance of high morale, an aggressive spirit and the bayonet. Small-unit tactics received little attention, professional soldiers believing that mass armies comprised of civilians in uniform would be incapable of executing complicated maneuvers under fire. Here again the British Army was exceptional, consisting as it did of well-trained, long-service professionals with considerable experience of colonial warfare. Finally, the German Army with its usual attention to detail had equipped its troops with entrenching tools — a measure scorned by other armies, greatly to their detriment.
Such, then, were the armies that marched to the sound of the guns of August 1914. What happened when they clashed for the first time would determine the course of the war, and ultimately of world history.