"Buch der Lieder" by Heinrich Heine is a poetry collection published in 1827. This landmark volume gathered all of Heine's previously published poems into chronological cycles, creating a psychological portrait of the poet's early work. Of its 237 poems, 142 explore themes of unrequited love, while others venture into political territory, including critiques of antisemitism. The collection features some of Heine's most famous works, including "Die Loreley" and "Die Grenadiere," establishing his reputation as one of Germany's foremost lyric poets.