Roman and German history suggests that the habitation of Central and Western Europe by the Slavs only began in the sixth century AD. However, certain elements attest to the fact that by the beginning of the sixth century, a Slav population was occupying vast territories extending from the Vistule, the Dniestr, the Danube, including present-day Slovakia, the Pannonia and the Coruthania.

The most recent archeological and historical knowledge has led to the development of a theory in which Slav tribes were only able to occupy such vast territories in Central and Western Europe (more specifically, to the east of the line connecting the present-day German island of Rugen, the Czech city of As and the city of Trieste in Italy) for about a century, but that they appeared progressively on this territory, evolving from sedentary indigenous peoples in the middle of Celtic and Germanic tribe movements.

This quite recent historical knowledge is confirmed by the writings of ancient Greek and Roman authors which proves a much earlier Slavic presence on these territories.

The first reference to the Slavs-Vénèdes is found in a work by Herodotus of Halicarnasse dated 400 BC. The designation Vénètes or Vénedès was the most widely used, and interestingly enough, it is still used today on the territories, places of contact between Western Europeans and the Slavs, situated on the territory of present-day Austria.

Mention of the Slav presence is also found in the writings of Pliny the Elder (79 AD) and of Tacitus Cornelius (55-116 AD). The first designation of the Slavs in the Latin form "Souveni" appears in the writings of Claude Ptolemy in 160 AD. This name was used under the form "Sloveni" by the Slavs of the Middle Danube before the 8th century, who lived on the present-day territories of Slovakia, of North and West Hungary, Moravia, Pannonia, Austria and Slovenia. The name is still used by the Slovakians and the Slovenians, who come from the ethnic group Sloveni.

Coexistence between the Slavs and the Celtic tribes has been discovered, by the most recent research, in the region of Liptov in Northern Slovakia, near the area of Liptovská Mara. Six Celto-Slav colonies were discovered at the same time as the site of a castle with a sanctuary in the center of it which was used for Celtic and Slav rites. The castle was surrounded by stone fortifications. Slav tribes also coexisted with the Germanic Quadis, according to the latest findings of the Czech archeologist J. Poulík.

In the third and second century, the Huns began leaving the Central Asian steppes, crossing the Danube in 377 AD and occupying Pannonia which became, for 75 years, their base for conducting looting raids in Western Europe. In 451, under the command of Attila, they crossed the Rhine, devastating Gaul, even crossing the Pyrenees and devastating the "Champs catalauniques." However, the death of Attila in 453 brought about the disappearance of the Hun tribe. In 568, a proto-Mongol tribe, the Avars, made their own invasion into the Middle Danube region.

The insurrected Slav population settled in the Middle Danube. The birth to the Samo Empire, which was first mentioned in writing as early as 623, was a response to the raids of the invading peoples. It was the first known political formation by the Slavs, who beat, in 631, the Frank Army of King Dagobert near Vogatisburg and thereby gained their independence from the Franks and the Avars. However, the Empire disappeared in 665 with the death of Prince Samo. The supremacy of the Avars in these countries only came to an end in 803, the year where Charlemagne, with much help from the Slavs in regions to the North of the Danube and that of the principality of Nitra, beat, once and for all, the Avars, who were eventually assimilated into the local Slav populations.

The Slavs of the Danube suffered heavy human and material losses by containing two large invasions by Asian tribes, thereby playing an essential role by forming a shield, which prevented nomad Asian tribes from carrying out their invasions and bloody raids in Western Europe.

A third invasion of Asian nomads in Europe, the six Magyar tribes, took place in this territory at the end of the 9th century.