The final phase of Roman architecture, following the adoption of Christianity as the state religion by Constantine in 313 CE and lasting until the coronation of Charlemagne in 800 CE as emperor of the Holy Roman Empire

• Early Christian architecture

• Medieval architecture

• Byzantine architecture

• Romanesque architecture

Characterized by churches planned for congregational worship, esp. the basilica

• Early Christian architecture

• Medieval architecture

• Byzantine architecture

• Romanesque architecture

Coincident with and related to the rise of Byzantine architecture

• Early Christian architecture

• Medieval architecture

• Carolingian architecture

• Romanesque architecture

The architecture of the European Middle Ages, comprising the architecture of the Byzantine, pre-Romanesque, Romanesque, and Gothic periods

• Early Christian architecture

• Medieval architecture

• Ottonian architecture

• Carolingian architecture

The architecture of the eastern sphere of the later Roman Empire, developing from late Roman and early Christian antecedents in the 5th century CE and influencing church building in Greece, Italy, and elsewhere for more than a thousand years

• Early Christian architecture

• Medieval architecture

• Byzantine architecture

• Romanesque architecture

Characterized by masonry construction, round arches, shallow domes carried on pendentives, and the extensive use of rich frescoes, colored glass mosaics, and marble revetments to cover whole interiors

• Early Christian architecture

• Medieval architecture

• Byzantine architecture

• Romanesque architecture

The architecture prevalent in Persia under the Sassanian dynasty that ruled 226 to 651 CE, forming a link between the older Mesopotamian traditions and the Byzantine

• Sassanian architecture

• Romanesque architecture

• Carolingian architecture

• Lombard architecture

A style of architecture emerging in Italy and western Europe in the 9th century and lasting until the advent of Gothic architecture in the 12th century

• Sassanian architecture

• Romanesque architecture

• Carolingian architecture

• Lombard architecture

Comprising a variety of related regional styles and characterized by heavy, articulated masonry construction with narrow openings

• Sassanian architecture

• Romanesque architecture

• Carolingian architecture

• Lombard architecture

The use of round arch and barrel vault, the development of the vaulting rib and shaft, and the introduction of central and western towers for churches

• Sassanian architecture

• Romanesque architecture

• Carolingian architecture

• Lombard architecture