The article deals with philosophy of history of the Ukrainian nation in the most crucial events in the history of Ukraine, the Berestechko battle (1651), as reflected in Lina Kostenko's historical novel in verses 'Berestechko', 1999. Written in the years of internal emigration (1966-1967) of its authoress, it tries to understand the nature of reality and existence, the use and limits of knowledge and factors influencing nation's identity and history. It also analyses the reasons of the Ukrainian defeat in Berestechko, Ukrainian historical and cultural failure, compared with other European nations, like the Polish, to begin with. The Ukrainian mentality and nature are examined here, based on Bohdan Khmelnytski's interior monologue. The work's connection with the poetic tradition of Polish romanticism is emphasized here, too. It is also viewed as a warning against the next failure of the Ukrainian.