Origins of Germanic tribes
Germanic peoples moved out of southern Scandinavia and northern Germany to the adjacent lands between the Elbe and Oder after 1000 BC. The first wave moved westward and southward (pushing the resident Celts west to the Rhine by about 200 BC), moving into southern Germany up to the Roman provinces of Gaul and Cisalpine Gaul by 100 BC, where they were stopped by Gaius Marius and Julius Caesar. It is this western group which was described by the Roman historian Tacitus (56–117 AD) and Julius Caesar (100–44 BC). A later wave of Germanic tribes migrated eastward and southward from Scandinavia between 600 and 300 BC to the opposite coast of the Baltic Sea, moving up the Vistula near the Carpathians. During Tacitus' era they included lesser known tribes such as the Tencteri, Cherusci, Hermunduri and Chatti; however, a period of federation and intermarriage resulted in the familiar groups known as the Alemanni, Franks, Saxons, Frisians and Thuringians.
The first phase of invasions, occurring between AD 300 and 500, is partly documented by Greek and Latin historians but difficult to verify archaeologically. It puts Germanic peoples in control of most areas of what was then the Western Roman Empire. The Tervingi entered Roman territory (after a clash with the Huns) in 376. Some time thereafter in Marcianopolis, the escort to Fritigern (their leader) was killed while meeting with Lupicinus. The Tervingi rebelled, and the Visigoths, a group derived either from the Tervingi or from a fusion of mainly Gothic groups, eventually invaded Italy and sacked Rome in 410, before settling in Gaul, and then, 50 years later, in Iberia, founding a kingdom that lasted for 250 years. They were followed into Roman territory first by a confederation of Herulian, Rugian, and Scirian warriors, under Odoacer, that deposed Romulus Augustulus on 4 September 476, and later by the Ostrogoths, led by Theodoric the Great, who settled in Italy. In Gaul, the Franks (a fusion of western Germanic tribes whose leaders had been aligned with Rome since the third century AD) entered Roman lands gradually during the fifth century, and after consolidating power under Childeric and his son Clovis’s decisive victory over Syagrius in 486, established themselves as rulers of northern Roman Gaul. Fending off challenges from the Allemanni, Burgundians, and Visigoths, the Frankish kingdom became the nucleus of what would later become France and Germany. The initial Anglo-Saxon settlement of Britain occurred during the fifth century, when Roman control of Britain had come to an end. The Burgundians settled in northwestern Italy, Switzerland and Eastern France in the fifth century.
Migration of early Slavs
in Europe between the 5th-10th centuries AD
The second phase took place between 500 and 700 and saw Slavic tribes settling more areas of central Europe and pushing farther into southern and eastern Europe, gradually making the eastern half of the continent predominantly Slavic. Additionally, Turkic tribes such as the Avars became involved in this phase. In 567, the Avars and the Lombards destroyed much of the Gepid Kingdom. The Lombards, a Germanic people, settled in Italy with their Herulian, Suebian, Gepid, Thuringian, Bulgar, Sarmatian and Saxon allies in the 6th century. They were later followed by the Bavarians and the Franks, who conquered and ruled most of Italy.
Bulgars' settlements in the 6th-7th centuries AD
The Bulgars, originally a nomadic group from Central Asia, had occupied the Pontic steppe north of Caucasus since the second century, but after, pushed by the Khazars, the majority of them migrated west and dominated Byzantine territories along the lower Danube in the seventh century. From this time and onward the demographic picture of the Balkans changed permanently becoming predominantly Slavic, while pockets of native people survived in the mountains of southwest Balkans, Albania and Greece.
During the early Byzantine–Arab Wars, Arab armies attempted to invade southeast Europe via Asia Minor during the late seventh and early eighth centuries, but were defeated at the siege of Constantinople (717–718) by the joint forces of Byzantium and the Bulgars. During the Khazar–Arab Wars, the Khazars stopped the Arab expansion into Europe across the Caucasus (7th and 8th centuries). At the same time, the Moors (consisting of Arabs and Berbers) invaded Europe via Gibraltar (conquering Hispania—the Iberian Peninsula—from the Visigothic Kingdom in 711), before being halted. These battles broadly demarcated the frontiers between Christendom and Islam for the next millennium. The following centuries saw the Muslims successful in conquering most of Sicily from the Christians by 902.
The Hungarian conquest of the Carpathian Basin from around 895 and the following Hungarian invasions of Europe, and the Viking expansion from the late 8th century conventionally mark the last large movements of the period. Christianity gradually converted the non-Islamic newcomers and integrated them into the medieval Christian order. After that, the German eastward expansion (german: (Deutsche) Ostsiedlung) started in the 11th century in Eastern Europe.