1. FREDERICK II (the Great), King of Prussia from 1740-1786, is one of the great military figures of history. The first half of his reign was largely devoted to war, with Austria under Maria Theresa as his chief adversary and Silesia as a major cause: the first and second SILESIAN WARS (1740-45) and the Seven Years' War (1756- 63).

It was especially during the latter war, when Prussia, allied with England, had to fight the superior alliance of Austria, France, Russia, Sweden, and Saxony, that Frederick proved his unusual skill and audacity as a military leader. One of his most brilliant and decisive victories was won near the Silesian village of LEUTHEN (Dec. 5, 1757). This victory against a vastly superior Austrian army under Prince Charles of Lorraine was due to Frederick's military genius as well as the excellent morale of his officers and men. Before the battle, in the presence of his generals, the King delivered a famous address, which illustrates Clausewitz's point. It ended thus: "Gentlemen, the enemy stands behind his entrenchments, armed to the teeth. We must attack him and win, or else perish. Nobody must think of getting through any other way. If you do not like this you may hand in your resignation and go home."

(Other significant battles of the Seven Years' War mentioned by Clausewitz were the battles of Rossbach, Liegnitz, Prague, Kolin, Hochkirch, and Minden.)

2. The term "corps" as used by Clausewitz does not refer to a specific army unit (such as a modern army-corps), but is used simply to describe any section of the army.

3. Both battles were part of Napoleon's campaign against Austria in 1809. At Eckmühl, near RATISBON in Southern Germany, a French army under Napoleon and his Marshal Davout defeated a strong Austrian army on April 22. This paved the way for Napoleon's invasion of Austria, where at the village of WAGRAM, near Vienna, he succeeded in beating the Archduke Charles so thoroughly (July 5-6) that Austria had to ask for an armistice shortly afterwards. (For further references to these battles see pages 20, 23, 55. See also note 17, which discusses the battle of Aspern-Essling, which intervened between Ratisbon and Wagram.)

4. Near MINDEN in Westphalia, DUKE FERDINAND OF BRUNSWICK, one of Frederick II's generals during the Seven Years' War, won a significant victory over the French under Marshal Contades. He had planned to attack the French positions in the early hours of August 1, 1759, when he received word that the French in turn were getting ready to attack him. He went through with his plans for mobilization, thus completely upsetting Contades' preparations for a surprise attack. In the ensuing battle the allied Prussian, English, and Hanoverian troops won a decisive victory, which resulted in the withdrawal of the French beyond the Rhine and Main rivers.

At the same time, about one-third of Ferdinand's army, organized as an independent corps under General von Wangenheim, was stationed to the left of the main army, near the village of TANNHAUSEN (also known as Thonhausen, or Thodthausen). This corps had not been informed of the impending French attack. An enemy corps under Broglie opened fire on Wangenheim's entrenchments around 5 A.M. It failed to follow up its surprise attack, however, thus enabling Wangenheim to draw up his troops and resist Broglie until the defeat of the main army under Contades forced the French to retreat.

5. At ROSSBACH, on November 5, 1757, FREDERICK II'S army of 22,000 men defeated a combined French and German army twice its size, under the leadership of the incompetent Princes of Soubise (France) and Hildburghausen (Saxony). While his opponents, thinking he was beating a hasty retreat, began their pursuit, Frederick's excellently trained cavalry under General von Seydlitz suddenly attacked their right flank. The enemy, with no time to draw up in battle-formation, was completely dispersed and defeated.

The moral effect of Frederick's victory was tremendous both inside and outside of Germany. It reestablished his reputation, which had suffered considerably after his defeat at Kolin (see note 15).

6. The Battle of LIEGNITZ, like those of Rossbach and Leuthen earlier, shows FREDERICK the Great's skill in defeating a superior force by using his highly mobile army in a concentrated attack, keeping the enemy as much in the dark about his intentions as possible.

Finding himself surrounded near Liegnitz (Saxony) by several Austrian armies numbering close to 100,000, he planned a careful withdrawal. During the night of August 14-15, 1760, he broke camp, leaving his fires burning, however, to deceive the enemy, who had planned a three-cornered attack for the morning of August 15. At dawn the Prussian King surprised one section of the Austrian army under Laudon on the river Katzbach, and defeated 30,000 men with an army half this size.

7. During Napoleon's campaign against the Second Coalition (Great Britain, Austria, and Russia), the French General MOREAU had concentrated his forces at the village of HOHENLINDEN, situated in the midst of a great forest on a plateau east of Munich. Despite the warnings of his generals, Archduke John of Austria entered the forest on Dec. 2, 1800, to seek the French. Meanwhile Moreau, hidden by the forest, moved part of his forces, outflanked the Austrians, and caught them between two fires. The Austrian army was thoroughly beaten, losing more than 20,000 men, and Moreau was free to continue his advance toward Vienna.

8. FREDERICK II achieved the necessary concentration of his forces by a peculiar battle-order known as "schiefe Schlachtordnung" (oblique formation). Though by no means new (it had been used occasionally since antiquity), it was Frederick who first applied this formation consistently in aimost all his battles. In his General Principles of Warfare, written in 1748, Frederick described it as follows: "We `refuse' one of our wings to the enemy and strengthen the wing with which we plan to attack." This would make possible the defeat of a vastly superior enemy: "An army of 100,000 men, thus attacked on its flank, can be beaten by 30,000 men." The most successful example of Frederick's use of this formation "in echelon" was the battle of Leuthen (see note 1).

9. At HOCHKIRCH, a village in Saxony, the Austrian army of Marshal Daun delivered a serious defeat to Frederick II's forces on October 14, 1758. Attacking at the crack of dawn, the Austrians caught the over-confident King of Prussia unprepared, and with a force of 78,000 they defeated his army of 40,000, inflicting heavy losses on the Prussians. About 9,000 men were lost and several of Frederick's generals were killed or wounded.

10. General Friedrich von Cochenhausen in his [German] edition of this book points out that most of the rules dealing with this cavalry reserve, though no longer valid in modern warfare, can be applied almost word for word to mechanized units.

11. At Friedland, in East Prussia, a Russian army under Bennigsen was defeated by Napoleon, on June 14, 1807, during the War of the Third Coalition against France. The Russians were withdrawing along the right bank of the river Alle, towards Königsberg, when they met a single French corps under the command of Marshal Lannes. Bennigsen thought this an excellent chance for an attack, but Lannes held out until Napoleon arrived with his main army. The Emperor concentrated his main attack on the Russian left wing, which was separated from the right wing by a ravine, and whose only possible retreat was through a narrow outlet between this ravine and the river. Napoleon's artillery, concentrating on this point, inflicted heavy losses on the Russians before they succeeded in gaining the other bank of the Alle.

12. During the Seven Years' War, Prussia found herself surrounded by enemies: Saxony and Austria to the south, France to the west, Sweden to the north, and Russia to the east. Frederick II overcame his difficult position by making full use of the advantages which fighting on "interior lines" offers to a highly mobile army led by a commander who does not shrink from taking the initiative: Without waiting to declare war he seized Saxony in 1756. His invasion of Bohemia in 1757 was checked by the Austrians at KOLIN (see note 14) and he had to fall back upon his own terri- tories. From there he advanced with lightning speed, first into Central Germany to defeat the French at ROSSBACH (see note 5) and from there back to Silesia, where he beat the Austrians at LEUTHEN (see note 1). On August 25, 1758 he defeated the Russians near ZORNDORF. Eventually, however, the numerical superiority of his opponents became too great and Frederick was forced to limit himself to a more defensive strategy, while his tactics remained offensive.

13. Baron Antoine Henri Jomini (1779-1869), of Swiss origin, entered the French army in 1804 as aide-de-camp to Marshal Ney, and eventually was attached to Napoleon's headquarters. When he did not get the advancement he deserved, he went to Russia in 1813, where he was made a general and became a close associate of Tsar Alexander I. He is famous for his very influential writings on military theory, the chief of which, Treatise on Grand Military Operations, was published in 1805. His basic idea concerning strategy was: "To lead the concentrated force of our army to each important point on the theater of war and there to use these massed forces in such a way that they attack only fractions of the enemy army."

14. This statement is only partly true for such battles as Jena, Ulm, Eckmühl, Marengo, and Wagram.

15. In the spring of 1757 FREDERICK the Great invaded Bohemia with three separate armies. Two of these advanced from Saxony (one led by the King himself) and a third from Silesia, under the command of the seventy-two year old Marshal SCHWERIN. The Austrian army under Prince Charles retreated before the invaders and took up a strong position near PRAGUE. Schwerin's army was late in arriving, and when it finally did, the Prussians defeated the Austrians (May 6, 1757), but allowed a large part of the Austrian forces to withdraw. On June 18, Frederick, though outnumbered, once more attacked the Austrian army, this time under Marshal Daun, near KOLIN. He was thoroughly beaten, largely because of the numerical superiority of the Austrians and the ability and courage of Marshal Daun.

16. WELLINGTON'S CAMPAIGN OF 1810-1811 was part of the Peninsular War (1808-1813) to free Spain and Portugal from the domination of Napoleon. Just as in RUSSIA, during Napoleon's campaign of 1812, the inhabitants of the Peninsula voluntarily destroyed their possessions and stores of supplies, to make provisioning of the enemy impossible and to hasten his defeat. This policy of "scorched earth," as it is called today, was eminently successful in both cases.

17. In the vicinity of ASPERN and Essling, two villages near Vienna, Napoleon suffered a great military defeat on May 21-22, 1809. After winning against the Austrians near Ratisbon (see note 3), he had made his entry into Vienna on May 13th. The enemy's army, under Archduke Charles, had withdrawn to the north bank of the Danube, and Napoleon, in order to attack it, had to cross the river. In a murderous battle Charles defeated the French, who lost one of their ablest leaders, Marshal Lannes. After receiving vast reinforcements, Napoleon attempted another crossing on July 4. This time he was successful, and on July 5-6 he won the battle of WAGRAM, thus terminating Austria's premature war of liberation.

18. During the spring of 1807, Napoleon ordered his Marshal Lefebvre to lay siege to the city of Danzig. The siege, beginning in March, lasted into May. The Russian commander-in-chief, BEN- NIGSEN, who was stationed in the vicinity, remained passive throughout, even though the capitulation of Danzig gave Napoleon a valuable base and released a number of his troops, which he used to great advantage shortly afterwards in the battle of Friedland (see note 11).

19. See note 17.

20. Louis II of Bourbon, Prince of Condé (1621-86), known as the "Great Condé," started on a brilliant military career in 1640, towards the end of the Thirty Years' War (1618-48). In 1643 he was made commander of the French forces against the Spaniards in northern France and won the decisive victory of Rocroi, which, at the age of 22, established him as one of the great military figures of history.

Albrecht von WALLENSTEIN (1583-1634), a Bohemian nobleman, was one of the outstanding military leaders of the Imperial Catholic party during the Thirty Years' War, though his military education, according to Clausewitz's and our own standards, was brief and superficial. He saw two years of armed service (1604-1606) against the Turks and Hungarians, and from 1617 on he was commander of an increasing number of mercenaries (mostly hired at his own expense from a rapidly growing fortune), which he put at the disposal of the Emperor Ferdinand II. (See also note 22.)

Count Alexander SUVOROV (1729-1800) won fame as commander of the Russian forces during Catherine the Great's wars with Turkey (1768-74, 1787-92). In 1799, he was given supreme command over the Italian armies of the Second anti-French Coalition and succeeded in driving the French out of Italy.

21. Andre MASSÉNA, Prince of Essling, a distinguished French General and Marshal during the Revolutionary and Napoleonic Wars. In the spring of 1800, during the war of the Second Coalition, he was ordered by Napoleon to defend the Italian city of GENOA against the Austrians. The latter suddenly attacked, cut his army in two, and forced him to withdraw into the town with his remaining right wing. The Austrian general Ott laid siege to the city, and Mass‚na kept him occupied by constant sorties. In spite of the growing shortage of food he held out until June 4, enabling Napoleon to win the battle of Marengo. In 1810 Mass‚na was made commander-in-chief of a French army of 70,000 invading PORTUGAL to drive the English under Wellington "into the sea." Again he had to pitch his will-power and determination against the terrible enemy of hunger. The British troops withdrew into the interior, leaving behind them a mountainous country bare of provisions. Only one major battle was fought and lost by the French (at Busaco). Most of the French losses of 25,000 men were due to sickness and starvation. It is largely because of Mass‚na's skillful retreat that not more troops were lost.

22. During the period of Swedish intervention (1630-1632) in the Thirty Years' War, Albrecht von WALLENSTEIN, the leader of the Catholic and Imperial forces (see note 20) and King GUSTAVUS ADOLPHUS of Sweden occupied positions opposite each other near NUREMBERG in Southern Germany. After Wallenstein had several times refused battle, the Swedes attacked his camp on Sept. 3, 1632. Fighting lasted into the night, inflicting heavy losses on both sides, but Gustavus Adolphus did not succeed in driving out Wallenstein.

23. Near EYLAU in East Prussia, a French army under NAPOLEON and his Marshals Davout and Ney claimed a victory over the Russians, led by BENNIGSEN, on Feb. 8, 1807. The success of both armies changed frequently during battle, due to the various reinforcements they received, and at nightfall neither of them had won a decisive victory; but the French losses exceeded those of the Russians, who had lost more than a third of their men. Bennigsen, however, realizing the exhaustion of his troops and fearing further reinforcement of the French army, withdrew, leaving Napoleon to claim victory.

24. General Gerhard von Scharnhorst (1755-1813), known for his reforms of the Prussian army, was a close friend and teacher of Clausewitz'. While still a captain, he participated in the War of the First Coalition against revolutionary France, and was among the heroic defenders of the town of Menin in Flanders. He described his experiences in 1803 in a memorandum entitled The Defense of the Town of Menin.

For several days during April, 1794, a force of 2,000 men under General Hammerstein defended the fortified town against the attacks of 20,000 Frenchmen under General Moreau. When Hammerstein's munitions and supplies ran short and the town had gone up in flames, he led his troops in a successful break through the enemy's lines (April 30), losing more than one-fifth of his forces. 

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