Diocese
2 of the 6 encyclopedias on this shelf carry an entry for Diocese. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
the territorial district or portion of the Church forming the spiritual jurisdiction of a bishop. Even as early as the New Testament history we find some plain indications of the rise of the diocesan system, in the cases respectively of James, Bishop of Jerusalem; Timothy, Bishop of Ephesus; Titus, of Crete; to whom may be added the angels or bishops of the Seven Churches DINOSAUR in Asia. The name of diocese was not given till the beginning of the 4th century. Previous to that period they were denominated parochia. DIOCLETIAN C. VALERIUS DIO- CLETIANUS (surnamed Jovius), a man of mean birth, a native of Dalmatia, proclaimed Emperor of Rome by the army in 284 A. D. He defeated Carinus in Mesia (286), conquered the Allemanni, and was generally beloved for the goo goodness of his disposition; but was compelled by the dangers threatening Rom Rome to share the government with M. Aurelius Valerius Maximian. In 292 C. Galerius and Constantius Chlorus were also raised to a share in the empire, which was thus divided into four parts. Diocletian administered Thrace, Egypt, Syria, and Asia. As the result of his reconstitution of the empire the barbarians were driven back from all the
Aiton's Encyclopedia (1910)
di'o-ses, the district and people falling under the care of a bishop. The term is a political one. It was borrowed from the Romans by the early Christian church. In the day of Constantine the empire was divided into thirteen political dioceses, each comprising several provinces. Thus Italy was a single diocese. The ecclesiastical diocese is a smaller division. The diocese of John Carroll of Baltimore, the first American bishop, appointed in 1790, included the thirteen American colonies.
What Has Changed in the Last Century
The definition holds: a diocese is still the territory and people under a bishop's care, and Aiton's note in 1910 that the word was borrowed from Constantine's civil administration remains the standard account. What has moved is scale and scholarship. Where Aiton's could point to John Carroll of Baltimore in 1790 as the sole American bishop with the thirteen states for his diocese, the Catholic Church in the United States now has roughly 200 dioceses, archdioceses and eastern eparchies, part of a worldwide total in the thousands, while shrinking congregations and clergy have pushed European bishops the other way, merging parishes and occasionally whole sees. Most historians of the early church now part company with Collier's confident 1921 list of James at Jerusalem, Timothy at Ephesus and Titus in Crete as diocesan bishops, treating the single-bishop-per-city pattern as something that emerged during the second century rather than an apostolic arrangement; and since the 1980s the Anglican Communion has had women as diocesan bishops.
Written for this edition, 2026.