The Officer's Manual

After the battle of Marengo, General Melas, although in the midst of his fortresses and magazines, saw himself compelled to abandon everything, in order to save the wreck of his army.

General Mack capitulated after the battle of Ulm, although in the centre of his own country.

The Prussians, in spite of their depôts and reserves, were obliged, after the battle of Jena, and the French after that of Waterloo, to lay down their arms.

Hence, we may conclude that the misfortune that results from the loss of a battle, does not consist so much in the destruction of men and of materiel as in the discouragement which follows this disaster. The courage and confidence of the victors augment in proportion as those of the vanquished diminish; and whatever may be the resources of an army, it will be found that a retreat will degenerate rapidly into a rout unless the general-in-chief shall succeed, by combining boldness with skill, and perseverance with firmness, in restoring the morale of his army.

MAXIM XXXII

The duty of an advanced guard does not consist in advancing or retiring, but in manœuvring. An advanced guard should be composed of light cavalry, supported by a reserve of heavy cavalry, and by battalions of infantry, supported also by artillery. An advanced guard should consist of picked troops, and the general officers, officers and men, should be selected for their respective capabilities and knowledge. A corps deficient in instruction is only an embarrassment to an advanced guard.

NOTE

It was the opinion of Frederick that an advanced guard should be composed of detachments of troops of all arms. The commander should possess skill in the choice of ground, and he should take care to be instantly informed, by means of numerous patrols, of everything passing in the enemy’s camp.

In war, it is not the business of an advanced guard to fight, but to observe the enemy, in order to cover the movements of the army. When in pursuit, the advanced guard should charge with vigor, and cut off the baggage and insulated corps of the retiring enemy. For this purpose, it should be reinforced with all the disposable light cavalry of the army.

MAXIM XXXIII

It is contrary to the usages of war to allow parks or batteries of artillery to enter a defile, unless you hold the other extremity. In case of retreat, the guns will embarrass your movements and be lost. They should be left in position, under a sufficient escort, until you are master of the opening.

NOTE

Nothing encumbers the march of an army so much as a quantity of baggage. In the campaign of 1796, Napoleon abandoned his battering train under the walls of Mantua, after spiking the guns and destroying the carriages. By this sacrifice, he acquired a facility of manœuvring rapidly his little army, and obtained the initiative as well as a general superiority over the numerous but divided forces of Marshal Wurmser.

In 1799, during his retreat in Italy, General Moreau being compelled to manœuvre among the mountains, preferred separating himself entirely from his reserve artillery, which he directed upon France by the Col de Fenestrelle, rather than embarrass his march with this part of his equipment.

These are the examples we should follow; for if, by a rapidity of march, and a facility of concentration upon decisive points, the victory is gained, the materiel of an army is soon re-established. But if, on the other hand, we are beaten and compelled to retreat, it will be difficult to save our equipments, and we may have reason to congratulate ourselves that we abandoned them in time to prevent them from augmenting the trophies of the enemy.

MAXIM XXXIV

It should be laid down as a principle, never to leave intervals by which the enemy can penetrate between corps formed in order of battle, unless it be to draw him into a snare.

NOTE

In the campaign of 1757, the Prince of Lorraine, who was covering Prague with the Austrian army, perceived the Prussians threatening, by a flank movement, to turn his right. He immediately ordered a partial change of front by throwing back the infantry of that wing, so as to form a right angle with the rest of the line. But this manœuvre being executed in presence of the enemy, was not effected without some disorder. The heads of the columns having marched too quick, caused the rear to lengthen out, and when the line was formed to the right, a large interval appeared at the salient angle. Frederick, observing this error, hastened to take advantage of it. He directed his centre corps, commanded by the Duke of Bevern, to throw itself into this opening, and by this manœuvre decided the fate of the battle.

The Prince of Lorraine returned to Prague, beaten and pursued, with the loss of sixteen thousand men and two hundred pieces of cannon.

It should be observed at the same time, that this operation of throwing a corps into the intervals made by an army in time of battle, should never be attempted unless you are at least equal in force, and have an opportunity of outflanking the enemy on the one side or the other; for it is then only you can hope to divide his army in the centre, and insulate the wings entirely. If you are inferior in number, you run the risk of being stopped by the reverses, and overpowered by the enemy’s wings, which may deploy upon your flanks and surround you.

It was by this manœuvre that the Duke of Berwick gained the battle of Almanza, in the year 1707, in Spain.

The Anglo-Portuguese army, under the command of Lord Galloway, came to invest Villena. Marshal Berwick, who commanded the French and Spanish army, quitted his camp at Montalegre, and moved upon this town to raise the siege. At his approach, the English general, eager to fight a battle, advanced to meet him in the plains of Almanza. The issue was long doubtful. The first line, commanded by the Duke of Popoli, having been broken, the Chevalier d’Asfeldt, who had charge of the second, drew up his masses with large intervals between them; and when the English, who were in pursuit of the first line, reached these reserves, he took advantage of their disorder to attack them in flank and defeated them entirely.

Marshal Berwick, perceiving the success of this manœuvre, threw open his front, and deploying upon the enemy’s flanks, while the reserve sustained the attack in front, and the cavalry manœuvred in their rear, obtained a complete victory.

Lord Galloway, wounded and pursued, collected with difficulty the remains of his army, and took shelter with them in Tortosa.

MAXIM XXXV

Encampments of the same army should always be formed so as to protect each other.

NOTE

At the battle of Dresden, in the campaign of 1813, the camp of the allies, although advantageously placed upon the heights on the left bank of the Elbe, was nevertheless extremely defective, from being traversed longitudinally by a deep ravine, which separated the left wing completely from the centre and the right. This vicious arrangement did not escape the penetrating eye of Napoleon. He instantly directed the whole of his cavalry and two corps of infantry against the insulated wing, attacked it with superior numbers, overthrew it, and took ten thousand prisoners, before it was possible to come to its support.

MAXIM XXXVI

When the enemy’s army is covered by a river, upon which he holds several têtes de pont, do not attack in front. This would divide your force and expose you to be turned. Approach the river in echelon of columns, in such a manner that the leading column shall be the only one the enemy can attack, without offering you his flank. In the meantime, let your light troops occupy the bank, and when you have decided on the point of passage, rush upon it and fling across your bridge. Observe that the point of passage should be always at a distance from the leading echelon, in order to deceive the enemy.

NOTE

If you occupy a town or a village on the bank of a river, opposite to that held by the enemy, it is an advantage to make this spot the crossing point, because it is easier to cover your carriages and reserve artillery, as well as to mask the construction of your bridge, in a town, than in the open country. It is also a great advantage to pass a river opposite a village, when the latter is only weakly occupied by the enemy; because as soon as the advanced guard reaches the other side, it carries this post, makes a lodgment, and by throwing up a few defensive works, converts it easily into a tête de pont. By this means, the rest of the army is enabled to effect the passage with facility.

MAXIM XXXVII

From the moment you are master of a position which commands the opposite bank, facilities are acquired for effecting the passage of the river; above all, if this position is sufficiently extensive to place upon it artillery in force. This advantage is diminished, if the river is more than three hundred toises (or six hundred yards) in breadth, because the distance being out of the range of grape, it is easy for the troops which defend the passage to line the bank and get under cover. Hence it follows that if the grenadiers, ordered to pass the river for the protection of the bridge, should reach the other side, they would be destroyed by the fire of the enemy; because his batteries, placed at the distance of two hundred toises from the landing, are capable of a most destructive effect, although removed above five hundred toises from the batteries of the crossing force. Thus the advantage of the artillery would be exclusively his. For the same reason, the passage is impracticable, unless you succeed in surprising the enemy, and are protected by an intermediate island, or, unless you are able to take advantage of an angle in the river, to establish a crossfire upon his works. In this case, the island or angle forms a natural tête de pont, and gives the advantage in artillery to the attacking army.

When a river is less than sixty toises (or one hundred and twenty yards) in breadth, and you have a post upon the other side, the troops which are thrown across derive such advantages from the protection of your artillery, that, however small the angle may be, it is impossible for the enemy to prevent the establishment of a bridge. In this case, the most skilful generals, when they have discovered the project of their adversary, and brought their own army to the point of crossing, usually content themselves with opposing the passage of the bridge, by forming a semicircle round its extremity, as round the opening of a defile, and removing to the distance of three or four hundred toises from the fire of the opposite side.

NOTE

Frederick observes, that “the passage of great rivers in the presence of the enemy is one of the most delicate operations in war.” Success on these occasions depends on secrecy, on the rapidity of the manœuvres, and the punctual execution of the orders given for the movements of each division. To pass such an obstacle in presence of an enemy, and without his knowledge, it is necessary not only that the previous dispositions should be well conceived, but that they should be executed without confusion.

In the campaign of 1705, Prince Eugene, of Savoy, wishing to come to the assistance of the Prince of Piedmont, sought for a favorable point at which to force the passage of the Adda, defended at that time by the French army, under the command of the Duke de Vendome.

After having selected an advantageous situation, Prince Eugene erected a battery of twenty pieces of cannon on a position which commanded the entire of the opposite bank, and covered his infantry by a line of entrenched parallels constructed on the slope of the declivity.

They were working vigorously at the bridge, when the Duke de Vendome appeared with his whole army. At first he seemed determined to oppose its construction, but after having examined the position of Prince Eugene, he judged this to be impracticable.

He therefore placed his army out of reach of the prince’s batteries, resting both his wings upon the river, so as to form a bow, of which the Adda was the cord. He then covered himself with entrenchments and abattis, and was thus enabled to charge the enemy’s columns whenever they debouched from the bridge, and to beat them in detail.

Eugene, having reconnoitred the position of the French, considered the passage impossible. He therefore withdrew the bridge, and broke up his camp during the night.

It was by this manœuvre, also, that, in the campaign of 1809, the Archduke Charles compelled the French to reoccupy the isle of Lobau, after having debouched on the left bank of the Danube. The march of the Archduke Charles was wholly concentric. He menaced Grosaspern with his right, Esling with his centre, and Enzersdorf with his left.

His army, with both wings resting on the Danube, formed a semicircle around Esling. Napoleon immediately attacked and broke the centre of the Austrians; but after having forced their first line, he found himself arrested by the reserves. In the meantime, the bridges upon the Danube had been destroyed, and several of his corps, with their parks of artillery, were still on the right bank. This disappointment, joined to the favorable position of the Austrians, decided Napoleon to re-enter the isle of Lobau, where he had previously constructed a line of field-works, so as to give it all the advantages of a well entrenched camp.

MAXIM XXXVIII

It is difficult to prevent an enemy, supplied with pontoons, from crossing a river. When the object of an army, which defends the passage, is to cover a siege, the moment the general has ascertained his inability to oppose the passage, he should take measures to arrive before the enemy, at an intermediate position between the river he defends and the place he desires to cover.

NOTE

Here we may observe, that this intermediate position should be reconnoitred, or rather, well entrenched beforehand; for the enemy will be unable to make an offensive movement against the corps employed in the siege, until he has beaten the army of observation; and the latter, under cover of its camp, may always await a favorable opportunity to attack him in flank or in rear.

Besides, the army which is once entrenched in this manner, has the advantage of being concentrated; while that of the enemy must act in detachments, if he wishes to cover his bridge, and watch the movements of the army of observation, so as to enable him to attack the besieging corps in its lines, without being exposed to an attempt on his rear, or being menaced with the loss of his bridge.

MAXIM XXXIX

In the campaign of 1645, Turenne was attacked with his army before Philipsburg by a very superior force. There was no bridge here over the Rhine, but he took advantage of the ground between the river and the place to establish his camp. This should serve as a lesson to engineer officers, not merely in the construction of fortresses, but of têtes de pont. A space should always be left between the fortress and the river, where an army may form and rally without being obliged to throw itself into the place, and thereby compromise its security. An army retiring upon Mayence before a pursuing enemy, is necessarily compromised; for this reason, because it requires more than a day to pass the bridge, and because the lines of Cassel are too confined to admit an army to remain there without being blocked up. Two hundred toises should have been left between that place and the Rhine. It is essential that all têtes de pont before great rivers should be constructed upon this principle, otherwise they will prove a very inefficient assistance to protect the passage of a retreating army. Têtes de pont, as laid down in our schools, are of use only for small rivers, the passage of which is comparatively short.

NOTE

Marshal Saxe, in the campaign of 1741, having passed the Moldau in quest of a detached corps of fourteen thousand men, which was about to throw itself into Prague, left a thousand infantry upon that river, with orders to entrench themselves upon a height directly opposite the tête de pont. By this precaution, the marshal secured his retreat, and also the facility of repassing the bridge without disorder, by rallying his divisions between the entrenched height and the tête de pont.

Were these examples unknown to the generals of modern times, or are they disposed to think such precautions superfluous?

MAXIM XL

Fortresses are equally useful in offensive and defensive warfare. It is true, they will not in themselves arrest an army, but they are an excellent means of retarding, embarrassing, weakening and annoying a victorious enemy.

NOTE

The brilliant success of the allied armies in the campaign of 1814, has given to many military men a false idea of the real value of fortresses.

The formidable bodies which crossed the Rhine and the Alps at this period, were enabled to spare large detachments to blockade the strong places that covered the frontiers of France, without materially affecting the numerical superiority of the army which marched upon the capital. This army was in a condition, therefore, to act, without the fear of being menaced in its line of retreat.

But at no period of military history were the armies of Europe so combined before, or governed so entirely by one common mind in the attainment of a single object. Under these circumstances, the line of fortresses which surround France was rendered unavailable during the campaign; but it would be very imprudent, therefore, to conclude that a frontier guarded by numerous fortresses may be passed with impunity; or that battles may be fought with these places in your rear, without previously besieging, or at least investing them with sufficient forces.

MAXIM XLI

There are only two ways of insuring the success of a siege. The first, to begin by beating the enemy’s army employed to cover the place, forcing it out of the field, and throwing its remains beyond some great natural obstacle, such as a chain of mountains, or large river. Having accomplished this object, an army of observation should be placed behind the natural obstacle, until the trenches are finished and the place taken.

But if it be desired to take the place in presence of a relieving army, without risking a battle, then the whole materiel and equipment for a siege are necessary to begin with, together with ammunition and provisions for the presumed period of its duration, and also lines of contravallation and circumvallation, aided by all the localities of heights, woods, marshes and inundations.

Having no longer occasion to keep up communications with your depôts, it is now only requisite to hold in check the relieving army. For this purpose, an army of observation should be formed, whose business it is never to lose sight of that of the enemy, and which, while it effectually bars all access to the place, has always time enough to arrive upon his flanks or rear in case he should attempt to steal a march.

It is to be remembered, too, that by profiting judiciously by the lines of contravallation, a portion of the besieging army will always be available in giving battle to the approaching enemy.

Upon the same general principle, when a place is to be besieged in presence of an enemy’s army, it is necessary to cover the siege by lines of circumvallation.

If the besieging force is of numerical strength enough (after leaving a corps before the place four times the amount of the garrison) to cope with the relieving army, it may remove more than one day’s march from the place; but if it be inferior in numbers after providing for the siege, as above stated, it should remain only a short day’s march from the spot, in order to fall back upon its lines, if necessary, or receive succor in case of attack.

If the investing corps and army of observation are only equal when united to the relieving force, the besieging army should remain entire within, or near its lines, and push the works and the siege with the greatest activity.

NOTE

“When we undertake a siege,” says Montécuculli, “we should not seek to place ourselves opposite the weakest part of the fortress, but at the point most favorable for establishing a camp and executing the designs we have in view.”

This maxim was well understood by the Duke of Berwick. Sent to form the siege of Nice in 1706, he determined to attack on the side of Montalban, contrary to the advice of Vauban, and even to the orders of the king. Having a very small army at his disposal, he began by securing his camp. This he did by constructing redoubts upon the heights that shut in the space between the Var and the Paillon, two rivers which supported his flanks. By this means, he protected himself against a surprise; for the Duke of Savoy, having the power of debouching suddenly by the Col de Tende, it was necessary that the marshal should be enabled to assemble his forces, so as to move rapidly upon his adversary, and fight him before he got into position; otherwise his inferiority in numbers would have obliged him to raise the siege.

When Marshal Saxe was besieging Brussels, with only twenty-eight thousand men, opposed to a garrison of twelve thousand, he received intelligence that the Prince of Waldeck was assembling his forces to raise the siege. Not being strong enough to form an army of observation, the marshal reconnoitred a field of battle on the little river Voluve, and made all the necessary dispositions for moving rapidly to the spot, in case of the approach of the enemy. By this means he was prepared to receive his adversary without discontinuing the operations of the siege.

MAXIM XLII

Feuquière says that “we should never wait for the enemy in the lines of circumvallation, but we should go out and attack him.” He is in error. There is no authority in war without exception; and it would be dangerous to proscribe the principle of awaiting the enemy within the lines of circumvallation.

NOTE

During the siege of Mons, in 1691, the Prince of Orange assembled his army, and advanced as far as Notre Dame de Halle, making a demonstration to succor the place. Louis XIV, who commanded the siege in person, called a council of war to deliberate on what was to be done in case the Prince of Orange approached. The opinion of Marshal Luxembourg was to remain within the lines of circumvallation, and that opinion prevailed.

The marshal laid it down as a principle that, when the besieging army is not strong enough to defend the whole extent of circumvallation, it should quit the lines and advance to meet the enemy; but when it is strong enough to encamp in two lines around a place, that it is better to profit by a good entrenchment – more especially as by this means the siege is not interrupted.

In 1658, Marshal Turenne was besieging Dunkirk. He had already opened the trenches, when the Spanish army, under the orders of the Prince Don Juan, Condé, and D’Hocquincourt, appeared in sight, and took post upon the Downs, at a distance of a league from his lines. Turenne had the superiority in numbers, and he determined to quit his entrenchments. He had other advantages also. The enemy was without artillery, and their superiority in cavalry was rendered useless by the unfavorable nature of the ground. It was, therefore, of great importance to beat the Spanish army before it had time to entrench itself and bring up its artillery. The victory gained by the French on this occasion justified all the combinations of Marshal Turenne.

When Marshal Berwick was laying siege to Philipsburg, in 1733, he had reason to apprehend that the Prince of Savoy would attack him with all the forces of the empire before its termination. The marshal, therefore, after having made his disposition of the troops intended for the siege, formed, with the rest of his army, a corps of observation to make head against Prince Eugene, in case the latter should choose to attack him in his lines, or attempt a diversion on the Moselle or Upper Rhine. Prince Eugene, having arrived in front of the besieging army, some general officers were of opinion that it was better not to await the enemy in the lines, but to move forward and attack him. But Marshal Berwick, who agreed with the Duke of Luxembourg, that an army which can occupy, completely, good entrenchments is not liable to be forced, persisted in remaining within his works. The result proved that this was also the opinion of Prince Eugene, for he did not dare to attack the entrenchments, which he would not have failed to do if he had any hopes of success.