War of the Spanish Succession , 1741 Leopold's career as a soldier in important commands began with the outbreak of the
War of the Spanish Succession in 1701. He had many improvements made in the Prussian army, notably the introduction of the iron
ramrod about 1700, and he now took the field at the head of a Prussian corps on the Rhine, serving at the sieges of
Kaiserswerth and
Venlo in 1702. In the following year, having obtained the rank of lieutenant-general, Leopold took part in the
Siege of Bonn and fought as part of the
Battle of Hochstadt, in which the
Austrians and their
Prussian allies were defeated by the French under Marshal
Claude-Louis-Hector de Villars on 20 September 1703. In the campaign of 1704 the Prussian contingent served first under
Louis William, Margrave of Baden-Baden, then
Prince Eugene of Savoy, and fought at
Blenheim. In 1705 Leopold was sent with a Prussian corps to join Prince Eugene in Italy, and on 16 August fought at the
Battle of Cassano. In the
Battle of Turin, he was the first to enter the hostile entrenchments (7 September 1706). He served in one more campaign in Italy, and then served under Eugene to join
Marlborough in the Netherlands, being present in 1709 at the
Siege of Tournai and the
Battle of Malplaquet. In 1710 Leopold succeeded to the command of the entire Prussian contingent at the French front, and in 1712, he was made a field marshal at the particular request of the crown prince of Prussia,
Frederick William, who had served with him as a volunteer. Shortly before this he had executed a
coup de main on the castle of Moers, which had been held by the Dutch in defiance of the claims of the Prussian king to its possession. The operation was effected with absolute precision and the castle was seized without a shot being fired. In the earlier part of the reign of Frederick William I, the prince of Dessau was one of the most influential members of the Prussian governing circle.
Great Northern War Although Prussia was hostile to Sweden, the Prussians were reluctant to participate in the Great Northern War. Only after the
Russians destroyed most of the Swedish army did Prussia enter the war in 1715. Leopold accompanied the king to the front, commanded an army of 40,000 men, and defeated the much smaller force of
Charles XII of Sweden in a hard-fought battle on the island of
Rügen on 16 November in alliance with the Danish army of
Stralsund. In peacetime, and especially after a court quarrel and duel with General
Friedrich Wilhelm von Grumbkow in 1725, he devoted himself to the training of the Prussian army.
Training the Prussian Army Although the reputation gained by the Prussian army in the wars fought between 1675 and 1715 was a good one, it was still considered one of the minor military forces in Europe by 1740, when the
War of the Austrian Succession broke out. Leopold's outstanding achievement just before this time was his training of the Prussian infantry. The "Old Dessauer" was one of the sternest disciplinarians in an age of stern discipline, and the technical training of the infantry under his hand made the Prussian infantry into a formidable fighting force whose effectiveness had not yet been demonstrated. Leopold was essentially an infantry soldier; in his time, artillery usually did not decide battles, but he nonetheless chose to neglect the cavalry service, with results that manifested themselves at the
Battle of Mollwitz in 1741.
Frederick II of Prussia led the cavalry himself at the battles of
Hohenfriedberg in 1745 and
Leuthen in 1757, but had it not been for the supporting infantry trained by Leopold he would never have had the opportunity to do so. Thus Leopold, with the steadfast support of King Frederick William I of Prussia, himself one of the greatest drillmasters of Europe, turned to good account the twenty years following the peace with Sweden. During this time two incidents in his career deserve special mention: firstly, his intervention in the case of the crown prince Frederick, who was court-martialed for desertion, but due to his efforts reinstated in the Prussian army; and secondly, his successful role in the
War of the Polish Succession on the Rhine, where he served under his old chief Eugene of Savoy and held the office of Field Marshal of the Empire.
Service under Frederick the Great With the death of Frederick William in 1740, Frederick the Great succeeded to the Prussian throne, and a few months later initiated the invasion and conquest of
Silesia, the first action in the long
Silesian Wars and the test of Leopold's lifelong efforts to improve the effectiveness of the Prussian army. The prince himself was not often employed in the king's own army, though his sons held high commands under Frederick. The king, indeed, found Leopold somewhat difficult to manage, and the prince spent most of the campaigning years up to 1745 in command of an army of observation on the Saxon frontier. Early in that year his wife died. Leopold was now over seventy, but his last campaign was destined to be the most successful of his long career. A combined effort of the Austrians and Saxons to retrieve the disasters of the summer by a winter campaign towards Berlin itself led to a hurried concentration of the Prussians. Frederick from Silesia checked the Austrian main army and hastened towards
Dresden. But before Frederick arrived, Leopold had decided the war by means of his overwhelming victory over Saxons at
Kesselsdorf on 14 December 1745. It was his habit to pray before battle, for he was a devout
Lutheran. On this last field his words were, "O Lord God, let me not be disgraced in my old days. Or if Thou wilt not help me, do not help these scoundrels, but leave us to try it ourselves." Leopold's career ended with this great victory; when Frederick arrived after the battle, he embraced the Old Dessauer personally. Leopold retired from active service, and the short remainder of his life was spent at Dessau. He was succeeded as prince of Anhalt-Dessau by his son,
Leopold II Maximilian. Another of his sons,
Dietrich of Anhalt-Dessau, was a Prussian general, but the most famous of his sons was
Moritz of Anhalt-Dessau. ==Marriage and issue==