The Slavs were probably dominated in succession by the Scythians and the Sarmatians (both Iranian tribes), by the Goths, by the Huns, and by the Avars, in whose westward expansion they shared and whose slaves they often were. By the 6th cent. Slavs had settled in Germany E of the Elbe River. In the Balkan Peninsula they invaded the Byzantine Empire in 576 and again in 746, and they settled in the country districts of Greece.
A sedentary, agricultural people, the Slavs tended to adopt a loosely democratic organization. Primitive Slavic religion shows Iranian influence. The Slavs were animists; their supreme god was the god of lightning. In material culture, especially in military matters, the Slavs were greatly influenced by the Goths.
In the 8th cent. Charlemagne temporarily subdued the Slavs E of the Elbe, and German eastward expansion, which permanently pushed the Slavs beyond the Oder River, came in the 12th cent. with Henry the Lion of Saxony, the Wendic Crusade, Albert the Bear of Brandenburg, and the Teutonic Knights. From the 12th cent. on, the area of the Bohemian and Polish states was greatly changed by German immigration.
The Bohemian, Moravian, and Slovak tribes were converted (9th cent.) to Christianity by Saints Cyril and Methodius. A large Slavic empire emerged at that time under the leadership of Moravia, but it was soon destroyed by the Magyars. The duchies (later kingdoms) of Poland and Bohemia, most powerful of the Western Slavic medieval states, cooperated in the 10th cent. to resist German conquest. In the south, Bulgaria, Serbia, Bosnia, and Croatia each reached a relatively high degree of political development before being absorbed (14th–15th cent.) by the Ottoman Empire. Most important was the East Slavic Kievan state, which rose in the 10th cent. and was destroyed by the Mongol invasion in the 13th cent. Thereafter the principalities of Halych-Volhynia and Moscow (see Moscow, grand duchy of) became prominent.
From the 17th cent. on Pan-Slavism increased and became to some extent a development in opposition to Pan-Germanism. The history of the West Slavs and the South Slavs during the past three centuries is dominated by their struggles for liberation from Turkish, German, and Magyar domination. The Slavs, however, have not been able to unify politically, mainly as the result of different national interests.