On 21 Sep 1674, the Grand Assembly, held at James City, Virginia, enacted Act I – An act for the safeguard and defense of the country against the Indians.  to defend the northern frontier of the colony against the Susquehannocks and other Indian groups. The act provides for 8 garrisons and specifies the number of men each county is to provide. Ammunition, provisions, tools, surgeons, medicines, horses, pay to footmen and horsemen, compensation for families of those slain, and compensation for owners of horses killed are all specified. Rules of engagement and articles, rules and orders to be observed (26 in all) by the men are specified.
Act I specifies that 34 men out of Northumberland County, 25 men out of Lancaster County, and 25 men out of Middlesex County be garrisoned at one fort or place of defense on the Potomac River at or near John Mathew’s land in the county of Stafford (now Fairfax County), of which fort Captain Peter Knight is to be captain or chief commander.
Virginia Historical Highway Marker E-70, Colonial Fort, stands near this site at 38° 46.763′ N, 77° 3.111′ W, next to the George Washington Memorial Parkway in Belle Haven, Virginia. 
CPT Peter Knight (1620–1705) is 10th great-grandfather of MKS in the Knight branch.
 Virginia Department of Historic Resources, Historical Highway Markers, database search > E-70 > Colonial Fort, Fairfax (County). Virginia Department of Historic Resources, 1999 (photograph).
 William Waller Hening (editor), The statutes at large; being a collection of all the laws of Virginia, from the first session of the legislature, in the year 1619; …, Vol II (New York: R. & W. & G. Bartow (printer), 1823), pp326-336; digital images, Hathitrust.org (https://hdl.handle.net/2027/mdp.35112104867892).