Ivan Mazepa (1639–1709) was hetman of Zaporizhian Host and the first modern leader of Ukraine to stand against Russia. Born in the Polish-Lithuanian Commonwealth, he rose to Ukrainian rank originally as an officer for the tsar. Yet when Russia failed to live up to its obligations under the 1654 Pereiaslav Agreement, he joined Charles XII of Sweden in war against Russia — before their joint defeat at the Battle of Poltava in 1709. In 1819, the English Romantic poet Lord Byron (1788–1824) wrote a narrative poem called “Mazeppa.”