ENAt the turn of the twentieth century, Lithuania received new freedoms from the Russian Czars, allowing for the creation of a distinct Lithuanian national identity The arts, especially music, played an important but as yet understudied part in the establishment of this national style, The Lithuanian composer Mikalojus Konstantinas Čiurlionis (1875-1911) displays this nationalism throughout his mature compositions., and this thesis will address the Lithuanian national movement in relation to Čiurlionis and his music. Čiurlionis worked tirelessly to establish and promote Lithuanian music. He organized exhibitions, concerts, and composition competitions to inspire Lithuanian composers to employ material from their folk tradition within new works. He also detailed in two articles the musical characteristics of Lithuanian folk music and how a composer could use these characteristics in classical compositions. This thesis examines Čiurlionis’s use of his self-prescribed Lithuanian folk music characteristics within his De Profundis and considers the integration of this folk tradition within his own compositional style, as stated in his 1910 article, “About Music.”. Additionally, it explores Lithuanian nationalism in music at the turn of the twentieth century, addressing issues of authenticity and a “national” style. Finally, through comparison with extant studies concerning Bartok and Sibelius, this thesis presents Čiurlionis within the greater context of European—particularly central European-nationalism.