Tannhäuser (Middle High German: Tanhûser; died after 1265) was a German Minnesänger and poet. He is not attested historically outside of his poetry, which is dated to between 1245 and 1265. His biography is consequently obscure. It is assumed that there is a connection to the old noble family of the Lords of Thannhausen, who are still residing in their castle in Tannhausen, near Ellwangen and Dinkelsbühl. There is a historical Tannhausen castle near Neumarkt in der Oberpfalz. He was active at the court of Frederick II of Austria, and the Codex Manesse depicts him in the habit of the Teutonic Order, which suggests he might have participated in the Fifth Crusade.
Tannhäuser's poems are parodies of the traditional genre. His Bußlied (poem on atonement) is unusual with regard to the erotic theme of the remaining content of the Codex Manesse. Tannhäuser was a proponent of the leich (lai) style of poetry.
Based on his Bußlied, Tannhäuser became the subject of legend, first attested in 1430, propagated in ballads from 1450. The legendary account makes Tannhäuser a knight and poet who found the Venusberg, the subterranean home of Venus, and spent a year there worshipping the goddess. After leaving the Venusberg, Tannhäuser is filled with remorse, and travels to Rome to ask Pope Urban IV if it is possible to be absolved of his sins. Urban replies that forgiveness is as impossible as it would be for his papal staff to blossom. Three days after Tannhäuser's departure Urban's staff blooms with flowers; messengers are sent to retrieve the knight, but he has already returned to Venusberg, never to be seen again.
The legend was made famous in modern times through Richard Wagner's three act opera Tannhäuser in 1845. Aubrey Beardsley started to write an erotic treatment of the legend which was never to be finished due to his illness; the first parts of it were published in The Savoy and later published in book form by Leonard Smithers under the title Under the Hill. The novel was never completed, but in 1907 the manuscript was published under the title The Story of Venus and Tannhäuser.