The Northern Neck of Virginia is the strip of land between the Potomac and Rappahannock Rivers. It contains the counties of Northumberland, Lancaster, Richmond and Westmoreland Counties. Some definitions also include King George and Stafford Counties. The Northern Neck of Virginia is not to be confused with the old Northern Neck Proprietary owned by the Fairfax family until after the American Revolution, which encompassed a much larger area.
If you will take out a map of Virginia, and follow the Rappahannock River to the Rapidan, and then draw a line more or less Northwest back up to the Potomac River in West Virginia, you will end up with the Northern Neck PROPRIETARY. In modern parlance, the "Northern Neck" is Northumberland, Lancaster, Richmond and Westmoreland counties. By anyone's definition, whether 200 years ago or today, it by no means encompasses anything south (or west) of the Rappahannock River.
The Northern Neck of Virginia Historical Society Website for Membership, Publications, Links, News and Events.