An army corps is divided as a rule into two divisions, and each division is also a complete little army in itself.
Study this little table, and you will see the composition of a British division.
| Total Officers | No. of | No. of Guns, | No. of Vehicles, | |
| and Men. | Horses. | including | including those | |
| Machine Guns. | of the Artillery. | |||
| 1 Headquarters | 82 | 54 | — | 7 |
| 3 Infantry Brigades | 12,165 | 741 | 24 | 309 |
| 1 Headquarters Divisional Artillery | 22 | 20 | — | 2 |
| 3 Field Artillery Brigades | 2,385 | 2,244 | 54 | 240 |
| 1 Field Artillery (Howitzer) Brigade | 755 | 697 | 18 | 67 |
| 1 Heavy Battery and Ammunition Column | 198 | 144 | 4 | 19 |
| 1 Divisional Ammunition Column | 568 | 709 | — | 110 |
| 1 Headquarters Divisional Engineers | 13 | 8 | — | 3 |
| 2 Field Companies of Engineers | 434 | 152 | — | 102 |
| 1 Signal Company | 162 | 80 | — | 53 |
| 1 Cavalry Squadron | 159 | 167 | — | 9 |
| 1 Divisional Train | 428 | 378 | — | 176 |
| 3 Field Ambulances | 702 | 198 | — | 72 |
| —— | —— | —— | —— | |
| 18,073 | 5,592 | 100 | 1,169 |
Such a division on the march would cover from head to tail about 15¾ miles.
The supreme head of all the army corps which form an army is a commander-in-chief, or generalissimo, who is assisted by what is called the supreme general staff. The commander-in-chief and his staff are the brain and driving force of the army as a whole. It will interest you to learn how the commander-in-chief and his staff are linked up with every part of the army.
The commander-in-chief and his staff occupy what is called the general headquarters of the army, which is stationed in some town behind the area in which fighting is actually going on. Battles are now waged over so many miles that a commander-in-chief cannot possibly see for himself what is happening all along his line. He has to rely upon others, who bring him or send him information by telegraph, telephone, motor car, motor cycle, or aircraft. All day, and all night too, a constant stream of information as to the movements of the enemy, the position of his own troops, the progress of the fighting, and so forth, arrives at the headquarters of a commander-in-chief, and officers are set apart to receive this information and arrange it so that he may have a clear and full knowledge of all that is going on. Large maps are spread out on tables, and officers are constantly engaged in marking the movements of each side by means of flags or coloured chalks, so that at a glance the situation at any given moment may be seen. It is by the study of these marked maps that the commander and his staff decide what movements the army shall make to resist or attack the enemy.
This picture represents the headquarters of a French division in a village. Notice the cavalry and cyclist scouts and the men receiving messages by telephone. Notice also the officers writing orders and poring over maps.
Each army corps, division, and brigade has a similar headquarters, where the same kind of work is done and information is gathered up to be sent to the general headquarters, or the G.H.Q., as soldiers call it.