Eastern Europe, the Slavic and Baltic lands stretching across Russia, Ukraine, Poland, and the Balkans, presents one of the frustrating gaps in the study of European religion: the pre-Christian faith of these peoples is very poorly documented. There is no Slavic or Baltic equivalent of the Norse Eddas, no body of native myth written down before conversion; what is known of the old Slavic gods, Perun the thunderer, Veles the god of cattle and the underworld, the many-headed Svarog and Dazhbog, comes from fragmentary Christian chronicles (like the Russian Primary Chronicle, which records Prince Vladimir setting up and then, at his conversion in 988, tearing down the idols of Kiev), from a few foreign observers, and from later folklore.
The Baltic peoples (Lithuanians, Latvians, Prussians) were the last pagans in Europe, holding to their old religion into the fourteenth and fifteenth centuries, long after their neighbours had converted, which preserved somewhat more of their tradition. Eastern Europe later became a great heartland of Orthodox Christianity (through the conversion of the Rus) and of Roman Catholicism further west. In the modern era the region has seen a vigorous movement of Pagan reconstruction, Rodnovery, the Slavic Native Faith, which attempts, on this thin evidentiary base, to revive the old worship. The region thus stands for a religious past more lost than most, reconstructed from fragments and folk memory.