The topic of this graduate thesis is Croatian medieval poem S(ve)t' se kon'ča (The World Ends), written in Glagolithic manuscript Code slave No.11, also known as Pariški kodeks (The Paris Code) treasured in the French national library in Paris. This thesis presents constructive deductions of published theses on origin and influence of the poem, supported by linguistic and literary analyses of the song. The poem S(ve)t' se kon'ča is written in angular form of the Glagolitic script and in middle Dalmatian ikavian-chakavian dialect, mostly in dodecasyllabic verses with ten stanzas of four verses and three stanzas of three verses having single rhyme. The transcript of the last verse is probably altered. The poem belongs to a literary genre of dispute even though the majority of authorities consider it a satirical poem. It originated in Zadar or its vicinity in the first third of the 14th century. An author was probably the Franciscan Tertiary from the reformist circle affected by heretical Joachimite teachings. The medieval Latin literature, Revelation and dualistic heresy had a strong infulence on the poem. The poem, which is distinguished by its content and form, has a special place in Croatian medieval poetry and it had a long lasting influence on Croatian poetry.