A more thorough explanation:

Definition: Archdeaconry is a term used in Ecclesiastical law. It refers to the jurisdiction or area of authority of an archdeacon, who is a high-ranking official in the church.

Example: The archdeaconry of Canterbury covers a large area of southern England, including the counties of Kent and Sussex.

Explanation: In this example, the archdeaconry of Canterbury refers to the area of authority of the archdeacon who is based in Canterbury. This area includes several counties in southern England, and the archdeacon has certain responsibilities and duties within this jurisdiction.

Example: The archdeaconry of York is one of the oldest in England, dating back to the 7th century.

Explanation: This example illustrates that archdeaconries have a long history in the church, and some of them have been in existence for centuries. The archdeaconry of York is particularly old, and has played an important role in the church's history in northern England.