Prussian Army

The Royal Prussian Army (1701–1919, German: Königlich Preußische Armee) served as the army of the Kingdom of Prussia. It became vital to the development of Prussia as a European political and military power and within Germany.

The Royal Prussian Army had its roots in the core mercenary forces of Brandenburg–Prussia during the long religious strife of the Thirty Years' War of 1618–1648. Elector Frederick William (1620–1688, reigned 1640–1688), developed it into a viable standing army, while King Frederick William I of Prussia (1688–1740, reigned 1713–1740), dramatically increased its size and improved its doctrines. King Frederick the Great (1712–1786, reigned 1740–1786), a formidable battle commander, led the disciplined Prussian troops to victory during the 18th century Silesian Wars and greatly increased the prestige and military reputation throughout Europe and among the hodge-podge array of various German states kingdoms, duchies, principalities and free cities of the leadership in the East of the rising Kingdom of Prussia.

However the Prussian Army had become outdated and under-resourced decades later by the beginning of the late 18th century into the early 19th century era to meet the challenge from the west beginning in the political and social upheaval in the French Revolution of 1789–1793, overthrowing of the French monarchy, execution of Louis XVI, and the Royal House of Bourbon. The continuing strife spilling over French borders of the following French Revolutionary Wars (1792-1802), and then the Napoleonic Wars, and rise of the First French Empire of France under Napoleon I (1769–1821), defeated Prussia in the War of the Fourth Coalition in 1806–1807.

However, under the subsequent leadership of Gerhard von Scharnhorst (1755-1814), Prussian military reformers began modernizing the Royal Prussian Army, which contributed greatly to the later final defeat and exile of Napoleon I during the War of the Sixth Coalition. Conservatives halted some of the reforms, however, and the Prussian Army subsequently became a bulwark of the conservative Prussian royal government.

In the 19th century, the Prussian Army fought successful wars against Kingdom of Denmark in the Second Schleswig War of 1864; versus the Austrian Empire (Austria) in the Austro-Prussian War of 1866; and the Franco-Prussian War of 1870-1871 with the Second French Empire of France, led by Emperor Napoleon III; which allowing Prussia to lead and dominate in the Unification of Germany, establishing the German Empire in 1871. The Royal Prussian Army formed the core of the new larger Imperial German Army, which was replaced by the Reichswehr after the defeat in World War I (1914-1918), in the First German Republic (Weimar Republic) during the 1920s and early 1930s.

The army of Prussia grew out of the united armed forces created during the reign of Elector Frederick William of Brandenburg (1640–1688). Hohenzollern Brandenburg-Prussia had primarily relied upon Landsknecht mercenaries during the Thirty Years' War, in which Brandenburg was devastated. Swedish and Imperial forces occupied the country. In the spring of 1644, Frederick William started building a standing army through conscription to better defend his state.

By 1643–44, the developing army numbered only 5,500 troops, including 500 musketeers in Frederick William's bodyguard. The elector's confidant Johann von Norprath recruited forces in the Duchy of Cleves and organized an army of 3,000 Dutch and German soldiers in the Rhineland by 1646. Garrisons were also slowly augmented in Brandenburg and the Duchy of Prussia. Frederick William sought assistance from France, the traditional rival of Habsburg Austria, and began receiving French subsidies. He based his reforms on those of Louvois, the War Minister of King Louis XIV. The growth of his army allowed Frederick William to achieve considerable territorial acquisitions in the 1648 Treaty of Westphalia, despite Brandenburg's relative lack of success during the war.

The provincial estates desired a reduction in the army's size during peacetime, but the elector avoided their demands through political concessions, evasion and economy. In the 1653 Brandenburg Recess between Frederick William and the estates of Brandenburg, the nobility provided the sovereign with 530,000 thalers in return for affirmation of their privileges. The Junkers thus cemented their political power at the expense of the peasantry. Once the elector and his army were strong enough, Frederick William was able to suppress the estates of Cleves, Mark and Prussia.