Eynsford Castle was built on the site of a former Anglo-Saxon manor.
The manor of Eynsford lay on a strategic point along the River Darent, overlooking a crossing point, and in 970 it was acquired by Christ Church, Canterbury.

In the early 11th century, a stone building was then built in the manor on top of an artificial terrace, and it is possible that there may have been earlier stone buildings constructed on the same site.
The building was surrounded by a ditch and possibly a rampart, each approximately 5 metres (16 ft) wide and up to 3 metres (9.8 ft) deep and high respectively.
It is uncertain how far the outer defences reached; they may have traced the shape of the later castle, including a late-Anglo-Saxon cemetery located to the south-east.
The complex formed a secure aristocratic residence called a burh and the use of stone, rather than timber, in a secular building such as this was very unusual for the period.
Like some other burhs, it may have had an entrance tower called a burh-geat, symbolising the status of the owner.

After the Norman invasion of 1066, Odo, the Bishop of Bayeux and the new Earl of Kent, probably acquired the manor, which had by this time been lost by its former owners in Canterbury.
The burh appears to have continued in use, either because the manor continued to be managed in the same way as before, or because the occupation of the former elite site demonstrated the Normans' power over the local community.
Odo's lands and those of the Archbishop of Canterbury bordered each other, and Eynsford fell within an area mainly controlled by Canterbury.
The Italian monk Lanfranc became the Archbishop of Canterbury in 1070, and set about attempting to recover the manor, probably finally doing so around 1082, when Odo was arrested by King William.
Lanfranc assigned a knight called Ralph, probably a lay retainer from Normandy, to run the estate, and appointed Ralph's son, William de Enysford, to the role on his father's death.

Lanfranc remained concerned about the threat posed by Odo, and authorised William to improve the defences at Eynsford.
The work was probably carried out between 1085 and 1087, and enclosed the former burh with a stone curtain wall to form a castle.
Eynsford Castle was built on the site of a former Anglo-Saxon manor. The manor of Eynsford lay on a strategic point along the River Darent, overlooking a crossing point, and in 970 it was acquired by Christ Church, Canterbury.
In the early 11th century, a stone building was then built in the manor on top of an artificial terrace, and it is possible that there may have been earlier stone buildings constructed on the same site. The building was surrounded by a ditch and possibly a rampart, each approximately 5 metres (16 ft) wide and up to 3 metres (9.8 ft) deep and high respectively. It is uncertain how far the outer defences reached; they may have traced the shape of the later castle, including a late-Anglo-Saxon cemetery located to the south-east. The complex formed a secure aristocratic residence called a burh and the use of stone, rather than timber, in a secular building such as this was very unusual for the period. Like some other burhs, it may have had an entrance tower called a burh-geat, symbolising the status of the owner.
After the Norman invasion of 1066, Odo, the Bishop of Bayeux and the new Earl of Kent, probably acquired the manor, which had by this time been lost by its former owners in Canterbury. The burh appears to have continued in use, either because the manor continued to be managed in the same way as before, or because the occupation of the former elite site demonstrated the Normans' power over the local community. Odo's lands and those of the Archbishop of Canterbury bordered each other, and Eynsford fell within an area mainly controlled by Canterbury. The Italian monk Lanfranc became the Archbishop of Canterbury in 1070, and set about attempting to recover the manor, probably finally doing so around 1082, when Odo was arrested by King William. Lanfranc assigned a knight called Ralph, probably a lay retainer from Normandy, to run the estate, and appointed Ralph's son, William de Enysford, to the role on his father's death.
Lanfranc remained concerned about the threat posed by Odo, and authorised William to improve the defences at Eynsford. The work was probably carried out between 1085 and 1087, and enclosed the former burh with a stone curtain wall to form a castle.
Eynsford Castle