Emery says the building was not a priory as it had been termed by the late 19th-century owner Troyte Chafyn Grove, and there appears no evidence of ownership by a religious house or the residence of a large community of monks on the site.

[2] However, there is evidence of a dormitory and communal living dating from the 14th century, and the extant buildings grew on a foundation that had religious obligations by way of chantry to the de Courtenay Earls of Devon from at least 1344.

The original building work of what stands today at Naish Priory is directly linked to Sir Peter Courtenay (1346–1404), a Knight of the Garter and Royal Household and Constable of Windsor Castle, Lord of East Coker, and his brother William Courtenay (1342–1396) who was Archbishop of Canterbury from 1381 to 1396 and Lord Chancellor of England in 1381 and Sir Peter's tenant at Naish from 1392.

[2] Archbishop William de Courtenay was also responsible for major contemporaneous building work at Christ Church, Canterbury, and the foundation at Maidstone College.

[11] The earlier endowment by Huw the 2nd Earl of Devon, of Naish and surrounding land in East Coker, as part of a chantry for his family's souls, took place in 1344, and is evidenced by charter.

In particular the corbelled heads which stand either side of the great east window have been identified as those of Henry IV and Joan of Navarre, Queen of England who were married in 1403.

[1] Naish is surrounded by rich Grade 1 farm land which contains significant trees, waterways, ancient hedgerows, hollows with sunken roads and paths.

[12] The original buildings at Naish, together with surrounding Grade 1 farm land to be worked for an income in perpetuity, were dedicated by Huw de Courtenay 2nd Earl of Devon in 1344 to the remembrance and prayer for the souls of his family.

Naish seems to have been occupied during this time by his younger brother James de Courtenay who is responsible for the alteration to a country house, perhaps as the family was rehabilitated under Henry VIII of England.