Although the political structure in Western Europe had changed, the collapse of the Empire was not as dramatic as previously thought. Invader craftsmanship was often Roman-like, with barbarian artifacts often modeled after Roman artifacts. Likewise, the intellectual culture of the new kingdoms was directly based on Roman intellectual traditions. An important difference with the past was the gradual decrease in tax revenues. Most of the new political entities paid their armies not with tax revenues, but with land. This decreased the need for large tax revenues, and thus the taxation system fell apart. Slavery also declined, and the city’s society went into crisis. Civilian infrastructure collapsed and each new building was built on a much smaller scale than before. Cities and merchants suffered from the lack of security conditions for trade and manufacturing. As it became dangerous to travel or carry goods over any distance, there was a slump in trade and manufacturing for export. Major manufactures that depended on long-distance trade, such as the production of ceramic vessels on a large scale, all but disappeared in some parts of the West.
Between the fifth and eighth centuries new peoples filled the political vacuum left by the centralized Roman government. Germanic tribes established regional hegemonies within the former borders of the empire, creating the so-called Roman-barbarian kingdoms. The Ostrogoths settled in the late 5th century under Theodoric and established a kingdom based on cooperation between Italians and Ostrogoths, which lasted until the last years of Theodoric’s reign. The Burgundians initially settled in Gaul, later founding a new kingdom between Geneva and Lyon. In Gaul, the kingdoms of the Franks and the Bretons arose. Other kingdoms were founded by the Visigoths in Spain, the Suebi in Galicia, the Angles and Saxons in Britain and the Vandals in North Africa. These kingdoms were gradually recognized by Byzantium, by the only remaining emperor, who was not interested in the substantial government of that by now impoverished and decentralized area that was the West, but it was sufficient for him that the new kings formally submitted to his command, in exchange for legitimacy. Despite the destructive role that invading peoples often played in the invaded lands, almost all of the new kingdoms were themselves extremely vulnerable and in some cases even very small.
Some, such as those of the Burgundians or Suebi, were assimilated by their neighbours; others, like those of the Vandals or the Ostrogoths, collapsed under the offensive of Byzantium, which attempted to rebuild the unity of the Empire. Those of the Visigoths and Franks instead survived, both for the rapid integration between the resident population and the invaders, and for the collaboration with the Church and with exponents of the Latin intellectual world. In 568 the Lombards, led by Alboin, settled in Italy, where they created an independent kingdom that progressively extended its dominion over most of the Italian mainland and peninsular territory. The Lombard dominion was divided into numerous duchies, which enjoyed a marked autonomy with respect to the central power of the sovereigns established in Pavia; over the centuries, however, the sovereigns progressively extended the authority of the king, progressively achieving a strengthening of the royal prerogatives and of the internal cohesion of the kingdom.
In areas such as Spain and Italy, the encounter between Roman culture and the customs of the invaders led to a fusion, while in other areas, where there was a greater weight of the barbarian populations, new languages, customs and ways of to dress. The Latin of the Western Empire was gradually replaced by the Romance languages, while Greek remained the language of the Eastern Empire, although Slavic languages were later added.