This tome, in which Mykhailo Hrushevsky analyses the last two years of Hetman Bohdan Khmelnytsky's rule, consists of the final chapters (10-13) of volume 9. Hrushevsky presents the most comprehensive discussion to date of Khmelnytsky's foreign policy in the aftermath of the Treaty of Pereiaslav (1654), a topic closed to research in Soviet Ukraine from the 1930s to the 1980s. He also discusses Khmelnytsky's renewed efforts to annex the western Ukrainian territories and to control the Belarusian lands conquered by the Cossacks. He concludes with an assessment of the hetman and his age that has long been controversial in Ukrainian historiography. The volume shows how Ukraine's relations with Muscovy were strained by the Muscovites' failure to help fend off devastating Polish and Crimean attacks, which prompted Ukrainian leaders to seek support elsewhere. Tensions were exacerbated by the Ukrainian-Muscovite dispute over Belarusian territory. When Charles X of Sweden attacked the Commonwealth in 1655, while Khmelnytsky sought to recover the western Ukrainian lands, a Swedish-Ukrainian alliance seemed to be in the making. A military convention was concluded, but Charles, under pressure from his allies among the Polish nobility, would not cede western Ukraine to the Cossacks. Once Muscovy declared war on Sweden in 1656, it opened peace negotiations with Poland to which Cossack envoys were not admitted, convincing Khmelnytsky's officers that the Muscovites had betrayed them. Khmelnytsky then began a complicated diplomatic offensive to break up Muscovite-Polish negotiations. After the Vilnius accord between Muscovy and the Commonweath (November 1656), he sought to form a Swedish-Transylvanian-Ukrainian league in cooperation with Brandenburg and supported the abortive effort by Gyrgy Rkczi II of Transylvania to gain the Polish throne. Khmelnytsky also negotiated with the Ottoman Porte, giving rise to the vexed question of his possible request for vassal status. Hrushevsky's exhaustive discussion of diplomatic affairs greatly advances understanding of the role of Ukraine and the countries of East Central Europe in the political crisis of the mid-seventeenth century. This volume was translated by Marta Daria Olynyk and edited by Yaroslav Fedoruk (consulting editor) and Frank E. Sysyn (editor in chief) with the assistance of Myroslav Yurkevich. In a comprehensive introduction to the volume, Yaroslav Fedoruk considers issues of foreign policy, as well as the larger problem of national historiographies and their limitations with regard to the highly complex European situation. Frank Sysyn analyses Hrushevsky's assessment of Khmelnytsky's rule in chapter 13 as a polemic with the conservative historian Viacheslav Lypynsky (1882-1931). The preparation of this volume for publication was funded by a generous donation from Dr. Maria Fischer-Slysh (Toronto, Ontario) in memory of her parents, Dr. Adolf and Olha Slyz.