Hagia Sophia in Istanbul, built in 537 CE under Emperor Justinian, is the masterpiece of Byzantine architecture. Its vast central dome, seemingly floating on a ring of 40 arched windows and supported by massive pendentives, revolutionized interior spatial design and remained the world's largest cathedral for nearly a thousand years.

The Basilica of Saint-Sernin in Toulouse, France (c. 1080–1120), is a classic example of a Romanesque pilgrimage church. Its massive scale, extensive barrel vaulting over the nave, clear geometric articulation of parts, and spacious ambulatory with radiating chapels reflect the structural and functional demands of the era.

Notre-Dame de Paris (begun 1163) and Chartres Cathedral (rebuilt after 1194) are seminal High Gothic cathedrals. Chartres, in particular, perfectly integrates the pointed arch, ribbed vault, and massive flying buttresses to achieve a soaring 37-meter-high nave illuminated by over 150 original stained glass windows.

A massive European cathedral is characterized by its exceptionally tall nave, expansive walls almost entirely composed of stained glass, and a network of exterior arched stone supports spanning over the side aisles.