On the western shore of the Chesapeake Bay, there are three peninsulas or necks carved out by the tidal rivers. The northernmost peninsula lies between the Rappahannock and Potomac Rivers and became known in the 17th Century as "The Northern Neck." Only 15-20 miles wide, it runs inland between the rivers for about 100 miles - until the two rivers meet at Windmill Point on the Lancaster side of the Rappahannock and empty into the Chesapeake Bay.
The Northern Neck encompasses the following Virginia counties: Northumberland formed in 1648, Lancaster formed in 1651, Westmoreland in 1653, Stafford in 1664, Richmond in 1692, and King George in 1721. The inclusion of King George and Stafford in the Northern Neck varies among commentators. They are included by the Northern Neck of Virginia Historical Society and the Virginia Historical Society.
The geographic area of the modern-day Northern Neck must not be confused with the Northern Neck Proprietary, which was a private land grant that included all of these counties and stretched much further north and east. It encompassed all the land between the headwaters of the Rappahannock and Potomac Rivers. The Royal Charter to the Northern Neck Proprietary was voided after the Revolution. Traditionally, references in the last 100 years have not included King George or Stafford Counties as a part of the Northern Neck. Significant portions of the early King George lay in what is now Westmoreland County.
The first county in the Northern Neck area was Northumberland, formed in 1648 from the Native-American region known as Chicacoan. Northumberland was soon found to be too large to govern, and Lancaster was formed in 1651 from part of it and part of York County, which dated to 1634. In those days, a section of Lancaster was on the south side of the Rappahannock, in the area that is now Middlesex County.
Many important historical figures were born on the Northern Neck, including U.S. presidents George Washington (Westmoreland), James Madison (Port Conway in King George), and James Monroe (Westmoreland), as well as the Civil War general Robert E. Lee and signers of the Declaration of Independence, Francis Lightfoot Lee and Richard Henry Lee. Richard Henry Lee was the sixth President under the Articles of Confederation. Also residing in Westmoreland was Colonel Nicholas Spencer, member of the House of Burgesses, secretary and president of the Governor's Council, and on the departure of his cousin Thomas Colepeper, 2nd Baron Colepeper (aka Lord Culpeper), acting Governor. During the Colonial period, the Northern Neck was referred to as the "Athens of the New World" because of its collection of rich landowners dedicated to learning, gentlemanly society, and civic duty. This of course was made possible because of the slave economy in place at that time.
One of the best sources for breaking down brick walls can be found in chancery suits. These were equity suits. For genealogists, these suits are a goldmine of family data and fill in many blanks that cannot be found in more typical record searches. These suits were filed to obtain court permission and direction to divide the assets of an estate, usually land and slaves. These were usually (but not always) "friendly lawsuits" most typically used when someone died without a will. In some cases (the non-friendly ones especially), these suits could last for decades, providing a running commentary on who married whom and who had children by whom, who died when, and so forth. Very often if one of the parties lived out of the county or state, that is so stated, frequently with precise information on just where.
There are two main repositories for Virginia chancery suits: The Library of Virginia for local suits brought within in a county court and the District Court at Fredericksburg which included the Northern Neck Counties.
Records in the collection of the Library of Virginia break down as follows (many have been digitized and can be viewed on line).
There are several published books on Northern Neck County marriages. Probably the best of them, which consolidates all of them and from other sources (but by no means complete), is by Robert K. Headley, Jr. All of these books are available at the Mary Ball Washington Museum and Library, Lancaster, Virginia.
Married Well and Often, Marriages of the Northern Neck 1649-1800. (Genealogical Publishing Company, 2003). It is still in publication to the best of my knowledge. It covers Northumberland, Lancaster, Westmoreland, Old Rappahannock and Richmond Counties.
I would highly recommend for anyone's personal library. However, the cut off date of 1800 may cause problems for some researchers. Some of the old-standby books he incorporates into his book are:
Marriage License Bonds of Lancaster County 1701-1848 by Stratton Nottingham, reprinted by Genealogical Publishing Company in 1992.
Marriage Bonds of Northumberland County 1783-1850, Nottingham, Reprint. GPC, 1976
Marriage Bonds of Westmoreland County 1786-1850, Nottingham, privately published 1928 (This has probably been reprinted, most likely by GPC)
Richmond County Marriages 1668-1853 by George H. S. King, privately published, 1964. I don't know if this has ever been reprinted but there may be used copies available on line. His book also includes short little genealogical notes about the parties being married.
Index to Marriages of Old Rappahannock and Essex Counties 1655-1900, by Eva Eubanks Wilkerson (Reprint. Southern Historical Press, 2006). Due to the loss of pre-1852 marriage bonds for Essex County, Wilkerson used court order books, wills and deeds to determine marriages, though of course the dates are not the date of the actual marriage. [Essex County was formed from Old Rappahannock, and the Old Rappahannock County records remained with Essex County--Richmond County being formed from the other part of Old Rap.]
Marriage Bonds of Middlesex County 1740-1852, Stratton Nottingham. Reprint. Virginia Genealogical Society, 1965. This may have been reprinted since them, perhaps even by another publisher.
Also the Parish Register of Christ Church Parish, Middlesex 1653-1812, National Society of Colonial Dames of America in the State of Virginia, 1899. This was reprinted by Southern Historical Press in 1988 with a new index, the previous index having omitted about 1,000 names.
King George County Marriages 1786-1850, Vol. I, Bonds and Ministers' Returns, by Elizabeth Nichols Lee, Iberian Publishing, 1995. (Now Papyrus Publishing, Athens, GA)
King George County Marriages, Vol. II. Implied. (Same author & publisher, 1995.)
For both Stafford & King George County, a partial substitute:
Register of St. Pauls Parish 1715-1798, George H. S. King, 1962
Also for Stafford, a useful substitute: 1720-1760
Overwharton Parish Register 1720-1760, William F. Boogher, private printing 1899. This has been reprinted I am sure.
One problem with the Nottingham books is that they do not include any of the minister's returns, which give the actual date of the mariage (usually). Of course Nottingham was writing in the 1920s, before the WPA undertook the effort making so many marriage register books (Lancaster and Middlesex being two of them.)
For more information, see the EN Wikipedia article Northern Neck.