Langbehn was born in Hadersleben in what was then the Duchy of Schleswig, on 26 March 1851, the third of four sons. His father, a philologist, was dismissed from his position as the assistant principal at the local gymnasium shortly after Julius's birth, a result of a campaign to suppress German nationalism in southern Denmark following the First Schleswig War and the Revolutions of 1848. The Langbehn family eventually settled in Kiel, where Julius entered the gymnasium in 1863. After graduation, he entered the University of Kiel for a degree in the natural sciences. At the age of 19, he enlisted in the Prussian Army following the outbreak of the Franco-Prussian War in 1870. He fought in the battles of Orleans and Le Mans in December 1870 and January 1871, respectively. Langbehn's military service left him with a profound distaste for war.
After the war, Langbehn returned to Kiel to study chemistry, though in 1872 he transferred to the University of Munich with the help of a wealthy merchant. There, he grew bored with chemistry and began to study art and archaeology. After his mother suffered a nervous breakdown, Julius traveled to Venice before returning to Munich in 1875. He studied archaeology under Heinrich Brunn; his doctoral dissertation examined early Greek statues of Nike, the goddess of victory. He worked briefly at the Imperial Archaeology Institute in Rome in 1881. Over the following decade, he traveled throughout Germany, collecting material for his first book, Rembrandt als Erzieher (Rembrandt as Teacher), published in 1890. His work was focused on initiating cultural reform in Germany.
Rembrandt als Erzieher, which was published anonymously "by a German", was a huge success. A revised edition in 1891 added two chapters, one praising anti-Semitism and another on the Catholic Church. Despite its initial popularity, the book quickly receded from the limelight. In 1891, he published 40 Lieder (40 Poems), again anonymously; this proved to be a complete failure. The poems, which were explicitly erotic, prompted the state prosecutor of Schleswig-Holstein to threaten to press charges. The legal problems were sufficient to force Langbehn to withdraw the book. Der Rembrandtdeutsche followed, this time "by a friend of truth", though it too was not well received. Langbehn moved to Vienna, then in the Austro-Hungarian Empire, where he lived briefly. He shortly fled the country after having been convicted in a lawsuit from his landlord. Around this time Langbehn took on a disciple, a painter from Frisia by the name of Nissen.
After departing Vienna, Langbehn traveled to Italy, southern France, Spain, and the Canary Islands in 1894. He then returned to Germany and continued his vagrant life there, producing no new works. In the mid-1890s, he began to attend Catholic churches, and in early 1900 he converted to Catholicism. He now directed his reformist tendencies toward the Catholic Church, and began to attack liberal segments. Langbehn died on 30 April 1907 of stomach cancer.
Langbehn's efforts at reform were a reaction to modernism; he particularly disliked materialism, democracy, and internationalism. He favored aristocracy, individualism, and peace. He believed that Germany should abandon industrialization and urbanization in favor of an agrarian society ruled by a monarch. While Langbehn's vision did away with the bourgeois, proletarians, and the Junkers, he strongly opposed a classless society, stating that "equality is death." Langbehn advocated pan-Germanism, along with a view that Germany ought to take a place of primacy in world affairs, owing to national superiority. His 1891 editions of Rembrandt als Erzieher included lengthy, strident attacks on Jews as corrupters of German culture. He argued that they had no place in Germany, as they were not members of the Aryan race. Further anti-Semitic sentiments were expressed in Der Rembrandtdeutshce. He was an early advocate of the Völkisch movement later espoused by the National Socialists under Adolf Hitler. Langbehn's far-right views, along with his virulent anti-Semitism, has led to him being characterized as "the proto-Nazi."
- Rembrandt als Erzieher (1890)
- 40 Lieder von einem Deutschen (1891)
- Dürer als Führer (1928)
- Der Geist des Ganzen (1930)
- Briefe an Bischof Keppler (1937)
- Stern, pp. 98–100
- Stern, pp. 100–103
- Stern, pp. 109–111
- Stern, pp. 112–115
- Blamires & Jackson, p. 374
- Mosse, p. 51
- Rembrandt als Erzieher, quoted in Mosse, p. 51
- Lunn, p. 133
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- Bernd Behrendt: Zwischen Paradox und Paralogismus. Weltanschauliche Grundzüge einer Kulturkritik in den neunziger Jahren des. 19. Jahrhunderts am Beispiel August Julius Langbehn. Lang, Frankfurt am Main u.a. 1984. (= Europäische Hochschulschriften; Reihe 1; 804) ISBN 3-8204-5604-X
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- Hubertus Kunert: Deutsche Reformpädagogik und Faschismus. Schroedel, Hannover u.a. 1973.
- Ulf-Thomas Lesle: Bestseller des Bürgertums und Kursbuch der Plattdeutschen: "Rembrandt als Erzieher" von August Julius Langbehn. In: Kieler Blätter zur Volkskunde 32 (2000). S. 51-83.
- Benedikt Momme Nissen: Der Rembrandt-Deutsche Julius Langbehn. Herder, Freiburg im Breisgau 1927.
- Momme Nissen: Des Rembrandtdeutschen und mein Weg zur Kirche, in: Joseph Eberle (Hrsg.) Unser Weg zur Kirche, Luzern 1948.
- Johannes G. Pankau: Wege zurück. Zur Entwicklungsgeschichte restaurativen Denkens im Kaiserreich. Eine Untersuchung kulturkritischer und deutschkundlicher Ideologiebildung. Lang, Frankfurt am Main u.a. 1983. (= Europäische Hochschulschriften; Reihe 1; 717) ISBN 3-8204-7663-6
- Fritz Stern: Kulturpessimismus als politische Gefahr. Scherz, Bern u.a. 1963. / München. dtv. 1986. ISBN 3-423-04448-9 / Stuttgart. Klett-Cotta. 2005. ISBN 3-608-94136-3 (Rezension Deutschlandradio Kultur )
- Vincenzo Pinto: Apoteosi della germanicità. I sentieri di Julius Langbehn, Kulturkritiker tedesco di fine Ottocento. Icaro, Lecce 2009. ISBN 88-95377-23-0