Russian-born German poet and dramatist of the Sturm und Drang (Storm and Stress) period, who is considered an important forerunner of 19th-century Naturalism and of 20th-century Expressionistic theatre.

Lenz studied theology at Königsberg University but gave up his studies in 1771 to travel to Strasbourg as a tutor and companion to two young barons von Kleist. In Strasbourg he became a member of Goethe's circle and was strongly influenced by the Sturm und Drang sentiments of that group of dramatists. Lenz made his reputation with plays from the Strasbourg years, an eccentric didactic comedy, Der Hofmeister oder Vortheile der Privaterziehung (published 1774, performed 1778, Berlin; “The Tutor, or the Advantages of Private Education”), and his best play, Die Soldaten (performed 1763, published 1776; “The Soldiers”). His plays have dramatic and comic effects arising from strong characters and the swift juxtaposition of contrasting situations. Anmerkungen übers Theater (1774; “Observations on the Theatre”) contains a translation of Shakespeare's Love's Labour's Lost and outlines Lenz's theories of dramaturgy, summarizing conceptions of theatre that he shared with other members of the Sturm und Drang movement. These include contempt for classical conventions, particularly the unities of time and place, and a search for utterly realistic depiction of character.

Consumed by the ambition to become Goethe's equal, Lenz made himself ridiculous by imitating both Goethe's writing style and his personal life in Strasbourg and at court in Weimar, where Lenz followed Goethe in 1776. His eccentricities were thought to be harmless and amusing until a tactless parody angered Duke Charles Augustus, who therefore expelled Lenz from the court in disgrace. Lenz, showing signs of mental illness, was eventually placed in the care of the Lutheran pastor Johann Friedrich Oberlin (Oberlin, Johann Friedrich). (These weeks in Oberlin's household supplied the material for Georg Büchner (Büchner, Georg)'s novella Lenz 【1839】.) Lenz later returned to Russia, spending the remaining years of his life in aimless drifting and poverty and, eventually, in insanity. He was found dead in a street in Moscow.