What is a “cathedral” a seat of?

The story behind the answer

“Cathedral” comes from Latin cathedra, meaning the ceremonial chair that signifies a bishop’s teaching and governing authority. The church that houses this chair serves as the center of a diocese—hence the term “see,” from sedes, “seat.” Cardinals may preside in major churches in Rome and parish priests lead local parishes, but the defining feature of a cathedral is the presence of the bishop’s cathedra.

In the Middle Ages, cathedrals were more than vast stone sanctuaries: they were administrative hubs, courts, and places of learning. Their architecture—Romanesque solidity or Gothic height with rib vaults, pointed arches, and flying buttresses—allowed for towering walls of stained glass that taught Scripture to largely illiterate populations. Not all grand churches are cathedrals, and even a modest church can be one if it contains the cathedra.