Book excerpt: John Fennell's history of thirteenth-century Russia is the only detailed study in English of the period, and is based on close investigation of the primary sources. His account concentrates on the turbulent politics of northern Russia, which was ultimately to become the tsardom of Muscovy, but he also gives detailed attention to the vast southern empire of Kiev before its eclipse under the Tatars. The resulting study is a major addition to medieval historiography: an essential acquisition for students of Russia itself, and a book which decisively fills a vast blank on the map of the European Middle Ages for medievalists generally.