Although the estate of Helmsley was granted to Robert, Count of Mortain following the Norman Conquest; there is no evidence that he built a castle in the area.

Aelred, who was the abbey's first novice master, was known to be involved in l'Espec's affairs (military and personally) and Helmsley was often used as a place of safety during periods of instability.

[12] The East Tower may have been heightened specifically for the visit of King Edward III, who stayed at the castle for around five days in 1334.

[16] After Richard III's death at the Battle of Bosworth, Helmsley Castle was restored to Edmund de Roos by Henry VII.

[17] Edmund died childless in 1508 and the castle passed to his cousin Sir George Manners of Etal on whose death in 1513 his son Thomas inherited it.

[23] The castle had by this time been inherited by George Villiers, 2nd Duke of Buckingham who married Mary, daughter of Thomas Fairfax in 1657.

[28] As the castle fell into disrepair the local community took advantage of the site to hold fêtes, pageants and even agricultural shows.

The vicar of All Saints' Church, Charles Norris Gray, often held events in the castle throughout the latter part of the 19th century.

[29] The castle passed into the hands of the Office of Works in 1923 (under the guardianship of Sir Charles Peers), who began the clearing of debris and trees from the site.