Colne Priory
The Priory and Convent of Earl's Colne was founded in 1111 by Aubrey de Vere and his wife Beatrice. THe image of the building on this page is not of the Priory but the Prodigy House that was built at its site after its dissolution.
The establishment of reiigious houses in 12th and 13th Centuries England was not uncommon. Colne Priory was founded by followers of the Benedictine Order as was Walden Abbey (Audley End, Saffron Walden - founded by Geoforey de Mandeville - 1136-1143). Clare Priory and Leez Priory are Augustinian and were founded in 1248 and 1220. Chicksands Priory was founded by Rohse de Vere in Bedfordshire in 1152, it was of the Gibertine Order. Rohse was the daughter of Aubrey and Beatrice.
Clare Priory was founded by Richard de Clare, 6th Earl of Gloucester, a catholic.
The Church and the Monarcy
Especially during the early years of Christianity the role of the church and regligious in the activities of kings and queens has to be taken into consideration when trying to understand why things happened the way that they did. The obvious are those of Henry VIII, but earlier monarchs shaped the "political" nature of both the church and the countries history.
I have added the reigning monarch to the list of vicars on my page on St. Mary's.
The Priests at St. Mary's, Belchamp Walter - 1370-1528
The clergy at St. Mary's was provided by Colne Priory presumably since its foundation around 1111. The church records start at 1370. The last priest recorded as being associated with the Priory was Vincent Wharton in 1528.
On the Dissolution of the Monasteries in 1536 the provision of clergy for St. Mary's Belchamp Walter was transferred to the Church of England.
What the church guide says about Colne Priory and the de Vere connection
The following is highly improbable. The description is of the chantry in St. Mary's Belchamp Walter.
Since researching the statements from the church guide I have found a lot more information on the chantry, Sir John de Botetourt and other aspects of what you now find in the church of St. Mary's Belchamp Walter.
I think that it is now safe to say that Sir John de Botetourt was NOT an "underlord" for the de Veres and probably never lived in Belchamp Walter.