Karl Grün

Karl Theodor Ferdinand Grün, also known by his alias Ernst von der Haide, was a German journalist, philosopher, political theorist and socialist politician. He played a prominent role in radical political movements leading up to the Revolution of 1848 and participated in the revolution. He was an associate of Heinrich Heine, Ludwig Feuerbach, Pierre-Joseph Proudhon, Karl Marx, Mikhail Bakunin and other radical political figures of the era.