William de Hertburne, an ancestor of George Washington, assumed tenancy of the Wessyngtonlands from the Bishop of Durham for an annual fee of £4. Soon after, he changed his name to William de Wessyngton (later Washington). Although he used the Norman French spelling (based on a Middle English rendition of the original), the estate is of Anglo-Saxon (specifically Anglic) origin, originally being "Hwæssaingatūn", meaning "estates of the descendents of Hwæssa" (Hwæssa being rendered Wassa in Modern English). In 1613 the Washington family moved south to Sulgrave Manor, and the manor was sold to the Bishop of Durham.
The Hall continued to be used as a residence until the 19th century, when it became tenement flats and gradually fell into disrepair. In 1936 the building was declared unfit for human habitation, and was rescued from demolition by Fred Hill, a local teacher, who created what is now the "Friends of the Old Hall" to press for restoration of the building. Preservation work stopped during World War II, but was completed in 1955. In 1957 the National Trust assumed responsibility for the building.
The Wessyngton (Washington) Family had not owned Washington Old Hall since the early 1400s when Sir William Mallory married Dionysia Tempest, the last Wessyngton heir at the Hall. Dionysia was daughter of Sir William Tempest and his cousin, Eleanor Wessyngton. The sale in 1613 was by Sir John Mallory and Anna Eure, investors in the Virginia charter; Sir John Mallory having been a descendant of Sir William Mallory and Dionysia Tempest.