Cavalry is a general name for horse-soldiers or troopers trained to act in a body. In the British army there are 31 regiments of European, and 40 of native Indian cavalry. The former comprise 2 regiments of Life Guards (red), 1 of Horse Guards (blue), and 7 of Dragoon Guards, classified as heavy cavalry; 3 regiments of Dragoons, and 5 of Lancers, classified as medium; and 13 Hussar regiments or light cavalry—all carrying carbines and swords. The war strength of each is 1 lieutenant-colonel, 1 major, 8 captains, 9 lieutenants, 7 sub-lieutenants, 1 adjutant, 1 paymaster, 1 quartermaster, 1 medical officer, 1 veterinary surgeon, 75 non-commissioned officers, 8 farriers, 8 shoeing-smiths, 8 trumpeters, 4 saddlers, 2 wheelers, 15 bandsmen, 480 troopers, and 22 drivers, 559 riding and 44 draught horses, and 11 wagons.
The native Indian cavalry are all light, and some have the front ranks armed with lances, the rear with sabres. Bengal has 19 regiments, each of 8 troops, consisting of 10 European officers (1 in command and 1 surgeon), 17 native officers, and 536 native non-commissioned officers and troopers. Madras has 3 regiments of only 6 troops each, the same number of European, but 12 native officers and 396 of other ranks. Bombay has 7 regiments with the same organisation and numbers as Bengal, but only 518 native non-commissioned officers and troopers. There are also 5 regiments of the Punjab Frontier Force, 2 of Central Indian Horse, and 4 of the Hyderabad Contingent—40 regiments in all—besides a troop of native cavalry at Aden. The auxiliary cavalry in Great Britain comprises 38 regiments of Yeomanry and 1 of Volunteer Light Horse, of various strengths. There is a cavalry depot at Canterbury for all the regiments, and a school of instruction for auxiliary cavalry at Aldershot.
After the American civil war, the United States' cavalry was reduced to 10 regiments of 936 privates each. The commissioned officers of a regiment consist of 1 colonel, 1 lieutenant-colonel, 3 majors, 12 captains, 14 first lieutenants, and 12 second lieutenants.
History.—For the place of cavalry in the ancient armies, see ARMY. In the middle ages horsemen—knights, esquires, and their attendants—formed the most important part of the great armies; but after the disappearance of the Roman cohort with its 132 highly trained horsemen, the organisation of cavalry, as we now understand the word, was neglected until 1445, when Charles VII. of France grouped his men-at-arms into companies 100 strong. The method of fighting, from 1645 until Frederick the Great introduced the charge or shock tactics, was to advance to close quarters, fire pistols from the saddle, and then commence cutting with the sword. The value of dismounted cavalry able to act as infantry was then recognised, and dragoons armed with muskets were much in vogue until the beginning of the 19th century. They then lost favour, and they were taught that the sword was their proper weapon, and the saddle their proper place. Mounted infantry, however, using their horses merely as a means of rapidly covering the ground, have been found so useful in the British army that in 1887 a school for this arm was formed at Aldershot. The great importance of this branch was experienced in the Transvaal war (1899-1900), where all the Boer army were practically mounted infantry, and their mobility gave them enormous advantage in proportion to their numbers. The future development of all armies is bound to be very largely in this direction. The usefulness of the lance as a weapon for regular cavalry in pursuit and other tactics has led the British war authorities to arm part of nearly all their cavalry regiments with it in addition to their other arms.
Formation.—A cavalry regiment in the field is divided into 4 squadrons, each of 2 troops. The men of each squadron when in line are 6 inches from knee to knee, and formed in two ranks, a horse's length apart. The officers are at a similar distance in front, and the 'serrefiles,' or supernumerary non-commissioned officers, in rear. There is an interval of 12 yards between squadrons. The pace is, walk 4 miles an hour, trot 8, gallop 12. The maximum distance covered by cavalry is 68 miles by day (6 A.M. to 10 P.M.) and 18 by night—86 for the 24 hours; but after such a march there must be a rest all next day. For a continuous march 35 miles a day, at 5 miles an hour, is a good rate.
Duties on Service.—In large armies, from one-eighth to one quarter of the whole force should be cavalry. Their duties are to cover the movements of their own army, and to find out those of the enemy—besides taking part in the actual battles by guarding the flanks, seizing all opportunities of charging, completing success by an active pursuit, or covering defeat. The screening and reconnoitring duties are performed by the cavalry divisions, each of two or more brigades, one or two days' march in front of the main body. The light Brigades (q.v.) are perhaps best for the actual scouting, but must be supported by heavy cavalry in order to meet that of the enemy, which would otherwise have the advantage of greater weight in the charge. Each brigade of two or more regiments is accompanied by a battery of Horse Artillery.
The battle of Mars la Tour in the Franco-German war of 1870, supplies the best examples of a cavalry fight on a large scale, and of a charge (that of Barby and Bredows' brigades) directed against infantry. The action of the German cavalry throughout the same campaign illustrates the screening and reconnoitring duties of the arm. The capture of Cairo by the rapid advance of the British cavalry after the battle of Tel-el-Kebir (1882), shows its value after a successful engagement.
Tactics.—Unless acting dismounted, cavalry must either attack or retire; it cannot otherwise defend itself. Against cavalry it must therefore manoeuvre with its first line, so as to attack to the best advantage—i.e. against the adversary's flank. Its second line following, en échelon, in order to have a clear front, protects the flanks of the first from counter attack, and supports its movement, completing its victory, or covering its retreat. Horse artillery on the protected flank fire upon the enemy up to the last moment before the charge. A third portion, formed into a reserve, follows, and behind it the other two can rally after the charge, which, even when successful, creates great confusion. Cavalry attacks artillery in two bodies—one in line formation charges the escort, and the other in extended order, the men a horse's length apart, converges upon the guns. Infantry can defend itself from a cavalry charge, unless surprised by a flank attack, which would generally be delivered by comparatively small bodies in successive lines, but such an opportunity rarely occurs (see TACTICS).