 At a time when the remaining architectural structures of the Roman Empire were falling into decay and much of its learning and technology lost, the building of masonry domes and the carving of decorative architectural details continued unabated, though greatly evolved in style since the fall of Rome, in the enduring Byzantine Empire.The domed churches of Constantinople and Eastern Europe were to greatly affect the architecture of certain towns, particularly through trade and through the Crusades.The most notable single building that demonstrates this is St Mark's Basilica, Venice, but there are many lesser-known examples, particularly in France, such as the church of Saint-Front, Périgueux and Angoulême Cathedral.