He began his military career as a boy, serving against the Prussians in the last years of the
Seven Years' War. Entering the
Prussian army after
the peace, he was, as a result of his princely rank, at once made a
major; and in 1775 he was elevated to
lieutenant-colonel. In 1778 Frederick Louis took part in the
War of the Bavarian Succession and at about the same time was made a
colonel. Shortly before the death of King
Frederick the Great, he was promoted to the rank of
major general and appointed Chief of a Regiment. For some years the prince did
garrison duty at
Breslau, until in 1791 he was made governor of
Berlin. In 1794 he commanded a corps in the Prussian army on the
Rhine and distinguished himself greatly in many engagements, particularly in the
Battle of Kaiserslautern on 20 September. Frederick Louis was at this time the most popular soldier in the Prussian army.
Blücher wrote of him that he was a leader of whom the Prussian army might well be proud. He succeeded his father in the principality, and acquired additional lands by his marriage with a daughter of
Count von Hoym. In 1806 Frederick Louis, now a
general of infantry, was appointed to command the left wing of the Prussian forces opposing
Napoleon, having under him
Prince Louis Ferdinand of Prussia; but, feeling that his career had been that of a prince and not that of a professional soldier, he allowed his
quartermaster-general, the incompetent
Oberst (Colonel) Christian Karl August Ludwig von Massenbach to influence him unduly. Disputes soon broke out between Hohenlohe and the
commander-in-chief the
Duke of Brunswick, the armies marched hither and thither without effective results, and finally Frederick Louis's army was almost destroyed by Napoleon at the
Battle of Jena on 14 October 1806. The prince displayed his usual personal bravery in the battle, and managed to rally a portion of his corps near
Erfurt, whence he retreated into Prussia. But the pursuers followed him up closely and Marshal
Joachim Murat intercepted his corps at
Prenzlau. On the morning of 28 October, a fortnight after Jena and three weeks after the beginning of hostilities, Hohenlohe refused two French demands that he surrender. However, the initial fighting went against the Prussians in the
Battle of Prenzlau. Massenbach, who had gone to negotiate with the French, suddenly turned up with the news that the French completely surrounded them, which was untrue. Influenced by his
chief of staff and assured by Murat "on his honour" that 100,000 French had encircled his forces, Hohenlohe capitulated with 10,000 men (in fact, Murat had no more than 12,000 near Prenzlau, including only 3,000 infantry). Frederick Louis's former popularity and influence in the army had now the worst possible effect, for the commandants of garrisons everywhere lost heart and followed his example. The
capitulation of Pasewalk occurred on 29 October, the
capitulation of Stettin on the night of 29–30 October, and
Küstrin surrendered on 1 November. Before the month of November was over, the
Siege of Magdeburg ended in a capitulation. West of the
Elbe River, the
Sieges of Hameln, Nienburg, and Plassenburg also ended badly for Prussia. After two years spent as a
prisoner-of-war in
France, Frederick Louis retired to
Sławięcice Palace (Schloss Slawentzitz) and its estates, living in self-imposed obscurity until his death. He had, in August 1806, just before the outbreak of the
War of the Fourth Coalition, resigned the principality to his eldest son, not being willing to become a
mediatized ruler under
Württemberg suzerainty. == Marriage and issue ==