The parish of Over is recorded as early as 780 when Ethelmund, son of Ingeld, granted an estate of 30 hides at over for Gloucester Abbey. The reference to the manor of Highnam first appears in the Domesday Book in 1086. From 1329-1337 John Wigmore, Abbot of Gloucester is believed to have built a Greta Grange at Highnam. John Arnold leased Highnam Manor in 1516. The manor passed to the Lucy family until Joyce Lucy married Sir William Cooke. Following his death, his heir, Sir Robert Cooke owned the manor until it was seriously damaged in the Civil War. The manor was demolished and the current Court was built for his son William Cooke in 1658.
The Court passed from the Cooke family to the Guise family in 1747. Following financial issues, The Court was sold in 1838 to Thomas Gambier Parry who completely remodelled the estate.