Die Soldaten (The Soldiers) is a four-act opera in German by Bernd Alois Zimmermann, based on the 1776 play by Jakob Michael Reinhold Lenz. In a letter accompanying his newly printed play (23 July 1776, aged 24) that he sent to his best friend, the German philosopher Johann Gottfried von Herder, Lenz described himself as "an enigma to even his most precious friends", while saying of the play, "Here, into your holy hands, the piece which carries half of my existence. [The ideas it contains are] true and will remain so, even if centuries may walk contemptuously across my skull". Zimmermann wrote and revised his opera in phases between 1957 and 1964; it was premiered in 1965 and dedicated to Hans Rosbaud. Zimmermann himself faithfully adapted the play into the libretto, the only changes to the text being repeats and small cuts. It is the composer's only completed opera and is considered an important work of the second half of the 20th century.