The crucial distinction of a cathedral church is neither its size nor its splendour but that it has a *cathedra, i.e. the bishop's throne or chair of office. The first English cathedrals were built in the 6c and 7c, e.g. Rochester and (the first) St Paul's, but all AS cathedrals were demolished under the Normans. Today, the cathedral is one of the most visible parts of the Norman legacy. Cathedrals were no doubt an assertion of power on the part of the Normans, but such buildings also affirm a powerful faith. [< Lat. cathedra = a (bishop's) seat]
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.