After having lived for some time in Vienna, where he wrote some light comedies and other works for the Burgtheater, he became a soldier and joined the Lützow Free Corps in the German uprising against Napoleon.

One of these was the "Schwertlied" ('Sword Song'), composed during a lull in fighting, only a few hours before his death,[1] and "Lützow's wilde Jagd", each set to music by both Carl Maria von Weber and Franz Schubert.

He wrote a singspiel, Der vierjährige Posten, which was set to music by Franz Schubert in 1815, but the piece was not performed until 1869, when it was staged at the Hofoper, Dresden.

[5] Having taken up quarters at Zobten, on 28 March 1813 Major von Lützow had determined on setting out on an expedition to Saxony and Thuringia, with four squadrons of his cavalry, and fifty cossacks.

Körner was frustrated, but earnestly entreated permission to accompany him, and his desire was fulfilled when he was appointed adjutant by Lützow, who highly esteemed him, and wished to have him near his person.

They marched from Halberstadt via Eisleben, Buttstädt to Schleiz, and finally reached Eichigt near Plauen in Vogtland within a few days—not without encountering the enemy, who were dispersed throughout these districts, but, also, not without effecting some important results.

Without expecting to meet with any opposition, he chose the shortest route to rejoin the infantry of his corps, having received assurance of safety from the enemy's commanding officers, and proceeded, without interruption, back to Kitzen near Leipzig; but here he found himself surrounded and menaced by a very superior force.

Several were wounded and taken, and others dispersed in the surrounding country; but Major von Lützow himself was saved by the assistance of a squadron of Uhlans, who had been in advance with the Cossacks.

Körner had received the first blow, which he was not prepared to parry, as he approached the enemy's commanding officer to deliver his message, and was severely wounded in the head.

"My deep wound burns;—my pale lips quake in death,— I feel my fainting heart resign its strife, And reaching now the limit of my life, Lord, to thy will I yield my parting breath!

And that fair form that won my earliest vow, That my young spirit prized all else above, And now adored as freedom, now as love, Stands in seraphic guise, before me now.

Guided to Gnandstein Castle and later to Carlsbad in Bohemia, he subsequently travelled to Berlin, and having recovered from his wound, rejoined the Lützow corps in Mecklenburg.

According to J.R. Miller in "Homemaking" (now published as "The Family"), Körner had a very close friendship with his sister Emma, and when he died, "she survived him only long enough to complete his portrait and to draw with the pencil of love a sketch of his last resting-place."

[9][10][11] Many of the poems from his years in the Lützow Free Corps were set to music by Carl Maria von Weber and Franz Schubert.

[citation needed] His Life, written by his Father, with his Selections from his Poems, Tales, and Dramas, translated from the German by G. F. Richardson, appeared in London in 1845.