Definition: In the medieval European Christian Church, a diocese was a district administered by a bishop. In addition to the bishop's church (always a cathedral), a diocese would contain several other churches whose priests were subject to the bishop's authority. Each of the regions ministered to by one of these priests was a parish.
In the Eastern Orthodox Church, parishes were overseen by bishops, and the diocese was administered by the patriarch.
Examples:
Bishop de Vout's diocese included the parishes of Wellton, Illton, and Chutney-upon-Mutton.
