 Goethe—particularly in some early poems, such as "Prometheus"—and Hölderlin used free verse occasionally, due in part to a misinterpretation of the meter used in Pindar's poetry; in Hölderlin's case, he also continued to write unmetered poems after discovering this error.The German poet Heinrich Heine made an important contribution to the development of free verse with 22 poems, written in two-poem cycles, called "Die Nordsee" ("The North Sea") (written 1825-1826).These were first published in "Buch der Lieder" ("Book of Songs") in 182