In 1845 Moltke was appointed personal adjutant to Prince Henry of Prussia, a Roman Catholic who lived at Rome. He spent much of his leisure there in a survey, of which the result was a splendid map of Rome (Berlin, 1852). In 1846 Prince Henry died, and Moltke was then appointed to the staff of the 8th army corps at Coblenz. In 1848, after a brief return to the great general staff at Berlin, he became chief of the staff of the 4th army corps, of which the headquarters were .then at Magde burg, where he remained seven years, during which he rose to lieutenant-colonel (1850), and colonel (1851). In 1855 he was appointed first adjutant to Prince Frederick William (afterwards crown prince and emperor), whom he accompanied to England on his betrothal and marriage, as well as to Paris and to St. Peters burg to the coronation of Alexander II. of Russia. Prince Fred erick William was in command of a regiment stationed at Breslau, and there as his adjutant Moltke remained for a year, becoming major-general in 1856. On Oct. 23, 1857, owing to the serious illness of King Frederick William IV., Prince William became prince regent. Six days later he selected Moltke to be chief of the general staff of the army.
Moltke devoted himself to the adaptation of strategical and tactical methods to changes in armament and in means of com munication, to the training of staff officers in accordance with the methods thus worked out, to the perfection of the arrangements for the mobilization of the army, and to the study of European politics. In 1859 came the war in Italy, which occasioned the mobilization of the Prussian army, and a consequent reorganiza tion, by which its numerical strength was nearly doubled. The reorganization was the work not of Moltke but of the king, and of Roon, minister of war ; but Moltke watched the Italian cam paign closely, and wrote the history of it ascribed on the title page (1862) to the historical division of the Prussian staff.
in the Austrian campaign of 1866, Moltke's plans were adopted, and he was almost invariably supported in their execution. The campaign in Denmark had revealed the amazing superiority of the breech-loader, with which only the Prussian troops were armed, over the muzzle-loader still used by all other armies. Moltke had mastered, as none of his contemporaries had done, the methods of Napoleon. In 1866 each of his decisions was Napoleonic. The first was to employ almost his whole force (280,000) against the preponderant enemy, Austria, with her Saxon satellite (270,000) and to paralyse the other German states with a mere fraction (48,000). With this small force he first captured the whole Han overian army (17,000) and then dispersed the south German armies (about oo,000). The second decision was to deploy 280, 000 men upon the very long frontier separating Prussia from Austria and Saxony, there to form three armies, the Elbe army at Torgau, the first army (Prince Frederick Charles) in Lusatia, and the second army (the Crown Prince) at Landshut and Walden burg in Silesia. His plan, resembling that of Napoleon in 1805, was to bring these three armies together by a concentric advance into the enemy's territory, Bohemia, where he believed the Aus trian army to be assembling. The three armies had no sooner reached these positions than the king was persuaded to order the second army to march eastwards towards Neisse to meet an ex pected Austrian invasion from Moravia. Moltke's plan seemed to be upset, but on June 15 the political crisis came to a head and Prussia declared war. On the same day Moltke learned that the Austrian army had assembled not in Bohemia, but in Moravia. He immediately instructed the Crown Prince to turn back and march westwards to his original positions, and the Elbe army to advance through Dresden to join Prince Frederick Charles, who was to advance southwards through Lobau. The Saxon army retreated from Dresden and joined the first Austrian army corp on the Isar. On the 17th Benedek, commanding the Austrian army, gave orders for its march from Moravia to the neighbourhood of Josef stadt. Moltke had expected this and calculated that the Austrian movement could not be completed in time to enable Benedek with his whole army to attack either of the Prussian armies. On June 22 Moltke ordered both Prussian armies to ad vance into Bohemia and to seek to unite in the direction of Gitschin. The Austrians marched faster than Moltke expected, and might have opposed the Crown Prince with four or five corps; but Benedek's attention was centred on Prince Frederick Charles, and he interposed against the Crown Prince's advance f our corps not under a common command, so that they were beaten in detail, as were also the Saxons and the Austrian corps with them, by Prince Frederick Charles. On July 1 Benedek collected his already shaken forces in a defensive position in front of Koniggratz. Moltke's two armies were now within a march of one another and of the enemy. On July 2 Frederick Charles, who had passed Gitschin, ordered his army to attack this position, whereupon Moltke, who had that day reached Gitschin from Berlin, in structed the Crown Prince, who was at Koniginhof, to advance with his whole force against the Austrian right flank. Next day the Austrian army was defeated in the greatest battle of the century.