Prince Friedrich Karl of Prussia (1828–1885)

Friedrich Karl was born on 20 March 1828 as the only son of Prince Charles of Prussia, the brother of future Prussian king William I. From 1842 to 1846, Frederick Charles was under the military tutelage of then Major Albrecht von Roon. In 1845, the Prince joined the army and was sent to an infantry company. Roon accompanied the Prince to the University of Bonn in 1846. He was the first Hohenzollern prince to study in a university. He became a member of the Corps Borussia Bonn in 1847 and was awarded Prussia's Lifesaving Medal for rescuing a child from the Rhine the same year. After his studies, the Prince went back to his regiment in 1848, where he was promoted to captain. His company was issued the breech-loading Dreyse needle gun and the Prince produced an article on its probable future impact, writing that the troops could be prevented from firing off all their ammunition through good training and discipline. He served on Friedrich Graf von Wrangel's staff during the First Schleswig War of 1848. He shifted to the cavalry branch in October 1848 and was promoted to major in June 1849. He partook in a campaign in the Baden Revolution of 1849, during which he was wounded twice while leading a Guards Hussar squadron at the battle of Wiesenthal against Baden rebels. He continued to lead his squadron up till 1852.

In 1851, the Prince wrote a radical field manual for light troops, underlining the importance of training individual soldiers to take the initiative and not wait for orders. During the following peace years he was promoted to colonel in 1852 and granted the command of the Guards Dragoon Regiment, where he introduced realistic field exercises and insisted on combat readiness. He became major general and commander of the 1st Guards Cavalry Brigade in 1854 and lieutenant general in 1856. He commanded the 1st Guards Infantry Division from 19 February to 18 September 1857, but resigned after encountering significant opposition to his approach on training. In 1859, he published the study On French Tactics, which highlighted the decisiveness of troop morale. In 1860, the Prince published a military book, titled, "Eine militärische Denkschrift von P. F. K.", which contained a series of reform proposals. As commander of III Army Corps from 1 July 1860 to 17 July 1870, the Prince implemented his reforms and turned his corps into a leader in Prussian military innovation.

Promoted to General der Kavallerie, the Prince took part in the Second Schleswig War of 1864 against Denmark, where he held command over the Prussian troops in the Austro-Prussian expeditionary force and defeated the Danes at the Battle of Dybbøl. In May 1864, he became supreme commander of the Austro-Prussian allied army and conquered Jutland.

He served with distinction in the Austro-Prussian War, where he commanded the First Army; consisting of the II, III and IV corps. Arriving first at Königgrätz, the First Army single-handedly held the numerically superior Austrians at bay for seven hours from 08:00 to 15:00, inflicting such massive casualties on the Austrians that it took the arrival of just one division from his cousin the Crown Prince Frederick William's Second Army to complete the victory and cause the Austrians to order a general withdrawal at 15:00. The First Army then marched on Vienna.

He was elected to the North German Reichstag in the February 1867 North German federal election, representing the East Prussian constituency of Labiau-Wehlau.

At the outbreak of the Franco-Prussian War, the Prince was given command of the Second Army, and defeated the French Army of the Rhine at the Battle of Mars-la-Tour on 16 August 1870, cutting off its escape route to the west. The battle was followed by another victory at Gravelotte-St.Privat on 18 August and the encirclement and annihilation of the Army of the Rhine at the Siege of Metz. After the fall of Metz on 27 October, his army was sent to the Loire to clear the area around Orléans, where French armies, first under Aurelle de Paladines, then under Chanzy, were trying to march north to relieve Paris. He won battles at Orléans on 2 December and Le Mans from 10–12 January 1871. For his services he was promoted to the rank of Generalfeldmarschall. After the war, the Prince was made Inspector-General and was given the rank of Field Marshal of Russia by Alexander II of Russia.

He died of a heart attack at Jagdschloss Glienicke on 15 June 1885.

On 29 November 1854 at Dessau he married Princess Maria Anna of Anhalt-Dessau (1837–1906), daughter of Leopold IV, Duke of Anhalt. He had met her at a hunt. They had five children:

He received the following decorations and awards:[2]

German honours

Foreign honours

• He is portrayed by German actor Barnaby Metschurat in the Danish miniseries 1864.