Nunney Castle was built in the 1370s for Sir John de la Mare, a soldier and royal servant who had prospered during the reign of Edward III. He received a license to crenellate his Somerset residence in 1373. The compact design placed four round corner towers around a central block, all closely enclosed by a moat. Its symmetry and vertical form recall contemporary French castles that de la Mare may have encountered on campaign. The building combined defensible features with fashionable chambers suited to an ambitious household.

The interior included a hall, private apartments, service rooms, fireplaces, windows, and latrines arranged on several levels. Although the moat and towers projected military strength, Nunney was not intended to withstand a large royal army for long. It displayed status in a prosperous agricultural landscape and provided security against local disorder. Ownership passed through several families, and occupants altered windows, floors, roofs, and circulation as standards of comfort changed. The shell therefore preserves evidence of medieval planning alongside later domestic adaptation.

By the sixteenth century Nunney belonged to the Paulet family and then passed to the Praters. The Reformation and changes in noble residence reduced the strategic value of many small castles, but Nunney remained occupied. At the outbreak of the English Civil War, its owner Richard Prater supported the king and a Royalist garrison used the castle. Parliamentarian forces under Colonel Thomas Rainsborough attacked in September 1645 during the final reduction of Royalist positions in the West.

Cannon fire breached the north wall, and the garrison surrendered after a short siege. Parliament ordered the castle slighted, though much of the exterior remained standing. Damage, abandonment, and the removal of reusable materials gradually exposed the interior. In 1910 a portion of wall collapsed into the moat, prompting clearance and repair. The fallen masonry revealed construction details and emphasized that the apparently complete outline was structurally vulnerable. The ruin entered state guardianship and became the subject of systematic consolidation.

Today the water-filled moat and four towers make Nunney one of England's most recognizable small late medieval castles. Conservation preserves it as a roofless ruin rather than reconstructing missing rooms, so fireplaces, window openings, and wall scars provide the main evidence for domestic life. The site illustrates the limits of architectural display in wartime: a residence designed to appear formidable was quickly opened by artillery. Its survival also records changing approaches to monuments, from postwar neglect and picturesque appreciation to public guardianship, engineering repair, and archaeological interpretation.