This doctoral thesis deals with bertsolaritza - Basque poetic improvization - in its relation to language revival and politics in contemporary Basque country. In terms of methodology, this paper is based on anthropological fieldwork combined with the study of secondary data. Theoretical framework uses concepts of ethnicity and nationalism, anthropology of art, theory of poetry and performance as well as concepts of political anthropology. The issue is built on three fields: history of basque nationalism, language revival and bertsolaritza. Bertsolaritza is depicted as an artistic activity that participates on the construction of collective identity of euskaldunak (speakers of Basque). The core analysis is focused on 2013 Championship (Bertsolari Txapelketa Nagusia) in improvised poetry and its link to the basque political discourse 2011-2013. Bertsolaritza is to be understood as an expression of sociopolitical reflections within the frame of izquierda abertzale (nationalist left) as well as an open artistic reflection of a variety of socially relevant issues.