The primary theme during this period is the introduction and absorption of classical Mediterranean and Early Christian forms with Germanic ones, which fostered innovative new forms. This in turn led to the rise of Romanesque art in the 11th century. In the outline of Medieval art it was preceded by what is commonly called the Migration Period art of the "barbarian" peoples: Hiberno-Saxon in the British Isles and predominantly Merovingian on the Continent.
In most of western Europe, the Roman architectural tradition survived the collapse of the empire. The Merovingians (Franks) continued to build large stone buildings like monasterychurches and palaces.
The unification of the Frankish kingdom under Clovis I (465–511) and his successors, corresponded with the need for the building of churches, and especially monastery churches, as these were now the power-houses of the Merovingian church. Two hundred monasteries existed south of the Loire when St Columbanus, an Irish missionary, arrived in Europe in 585. Only 100 years later, by the end of the 7th century, over 400 flourished in the Merovingian kingdom alone. The building plans often continued the Roman basilica tradition.
Many Merovingian plans have been reconstructed from archaeology. The description in BishopGregory of Tours' History of the Franks of the basilica of Saint-Martin, built at Tours by Saint Perpetuus (bishop 460–490) at the beginning of the period and at the time on the edge of Frankish territory, gives cause to regret the disappearance of this building, one of the most beautiful Merovingian churches, which he says had 120 marble columns, towers at the East end, and several mosaics: "Saint-Martin displayed the vertical emphasis, and the combination of block-units forming a complex internal space and the correspondingly rich external silhouette, which were to be the hallmarks of the Romanesque".