Cathedrals emerged as a major form of scared buildings in the West --evolving partly from earlier Basilicas. One of the earliest instances of the term ecclesia cathedralis is said to occur in the acts of the council of Tarragona in 516. Another name for a cathedral church is ecclesia mater, indicating that it is the mother church from which other congregations have been established. Cited from Wiki: Cathedral The rise of cathedrals paralleled the rise of three dynasties of kings who evolved the idea of Holy Roman Emperors from the 5th through the 11th centuries: Merovingian Carolingian Ottonian The rise of the Crusades and Pilgrimage Routes led to new impulses and helped contribute to two further developments: Romanesque 11th c Gothic 12th c.