German writer, diplomat, biographer, and, with his wife, Rahel (Varnhagen von Ense, Rahel), a leading figure of a Berlin salon that became a centre of intellectual debate.

Varnhagen began his literary career (1804) by becoming joint editor of a poetry annual. Enlisting in the Austrian army (1809), he was wounded at the Battle of Wagram the same year and later accompanied his superior officer, Prince Bentheim, to Paris. He spent a year in the Prussian civil service (1812) but later resumed his military career. His experiences in Hamburg and Paris as an adjutant are recorded in Geschichte der Hamburger Ereignisse (1813; “History of the Hamburg Events”), and his experiences in the Napoleonic Wars are described in Geschichte der Kriegszüge des Generals von Tettenborn (1815; “History of the Military Expeditions of General von Tettenborn”).

Entering the Prussian diplomatic service, he was present at the Congress of Vienna (1814–15) and was resident at Karlsruhe until his recall in 1819. In 1814 he married Rahel Levin, whose salon was a gathering place for the writers, diplomats, and intellectuals of the day. Retiring from diplomatic service, Varnhagen became more involved in literature, although he was occasionally recalled for important political assignments.

Varnhagen's biographies include those of General Friedrich Wilhelm von Seydlitz (1834), Sophia Charlotte, queen of Prussia (1837), and General Friedrich Wilhelm Bülow von Dennewitz (1853). His numerous biographies are smoothly written and well organized but rely heavily on anecdote. A collection of his correspondence with the geographer and explorer Alexander von Humboldt has also been compiled.