The first sisters of the Order of St. John in England were dispersed across the commanderies . But in 1180, Henry II established a priory for them at Mynchin Buckland ( Mynchin Sororum) in the Taunton Vale, on condition that all the sisters should gather at the new house in Somerset. Mynchin Buckland then became the only house of Hospitaller sisters until the dissolution of the Order in England.
The first prioress of Buckland was named Fina who died in 1240 having governed the house for sixty years.The names of the first sisters are also known, Sister Millicent who had previously been living at Sterndon, Herts, Sister Johanna from Hampton, Sister Basilia from Carbroke, Sister Amabilia and Sister Amicia from Thengay, Sister Christina from Hogshaw, Sister Petronella from Gosford and Sister Agnes who came from Clanefield. We known little about the social background of the sisters or what part they played in the administration of the estates. Some of the sisters were fully confessed nuns or canonesses of justice, others were of office and there were also lay sisters and donats. They wore a black habit with the white eight-pointed cross of the Order sewn onto the front.
The priory was not an independent establishment, there was also a commandery of Hospitaller brethren at Buckland, under the charge of a commander. It was the duty of the brethren to give spiritual and temporal assistance to the sisters and to dispense the charitable requests and hospitality in fulfillment of the wishes of the donors and benefactors. Buckland became, after the Priory at Clerkenwell the largest establishment of the Order of St. John in England.
The earliest endowment to the priory was a grant from Matilda, Countess of Clare who in 1192 gave an annual pension to the sisters of 13s.4d. from the church of St. Peter at Carbrooke. Other early grants were the church of Tolland c 1180, the church of Donnington in the diocese of Lincoln, the church of Halse and land in Sherbourne and Primesley.
In 1198 Fra.Gilbert de Vere, prior of the Hospital gave the sisters an annual pension of 100s. from the manor of Rainham in Essex and about 1240 the prior Fra.Terri de Nussa awarded a yearly payment of 12s.8d. to be made by the commander of Buckland for the support of the sisters.
On 16 July 1227 Loretta Countess of Leicester, widow of Earl Robert who gave, "to God, the Blessed Mary and St. John the Baptist, and to the Blessed Poor of the Hospital house of Jerusalem for the Sustenation of the Sisters of Bockland, and for finding of a Chaplain to celebrate daily in the greater Church at Bockland at the Altar of the Blessed Virgin for the health of my soul and soul of Lord Robert, my husband, sometime Earl of Leicester, and for the health of the souls of my father and mother, and all of my ancestors and successors, all my land of Notestone and all my land of Ynesford this side of the water and that side of the water, and sixty-four acres of my demesne above Ruwedene and all my land of Ridescote, and of Hele, and of Charlecote, and of Tunecote, and of Boteburne, and all the land which Philip at Way holds with the tenants of the aforesaid land, etc,etc...To be had and possessed freely and quietly in perpetual and pure alms, as any alms may be freely and quietly given."
In 1267 the prior Fra. Roger de Vere visited Buckland to mediate on the deteriorating relations between the sisters and the brethren of the commandery. The prior ordered that henceforth the sisters should have their own steward, with a groom and a horse. If he should prove incompetent or unreliable then the prioress might suspend him but not dismiss him without the consent of the prior. The sisters were also to have a chaplain to celebrate the souls of the benefactors and of the first prioress, Fina. The steward and chaplain were to have their lodgings in the commandery.
In 1228 Henry III granted to the prioress and the sisters 21/2d. daily to be paid by the sheriff of Hereford and 2d. daily which Margaret, the king's sister Isabela's nurse was to receive for the support of three girls at the priory. The next year the sisters were granted a weekly cart load of dead wood from the park of Newton, and three cart loads of faggots. This grant of wood was reconfirmed in 1387 and in 1408 Henry IV reconfirmed the grant once again, defining the wood to be taken as thorn, alder, maple and hazel. The importance of fuel was again recognized when the prior of the Hospital granted the sisters 15 acres where furze grew for fuel. In the previous century Henry de Erlegh had granted the brethren of the commandery 30 wagon-loads of dead wood from his moors near North Petherton.
In 1232 William Earl of Arundel granted 40s. a year from his land for the support of his daughter Agnes as a sister at Buckland, and after his death, Henry III ordered the continuance of the payments for the remainder of Agnes's life. In 1234 the treasurer and chamberlain were ordered by the king to provide each sister with a new tunic and slippers every year.
In 1234 the house was partially burnt down and the sisters received a grant from the crown of thirty oak tress from the park of Newton to rebuild and a further forty oaks were given to them in 1236.
In 1311 Thomas of Berkeley gave £4 a year rent from lands at Ham for the maintenance of his daughter Isabel, during her life as a sister at the priory. She was prioress from 1330 to 1337.
The enquiry into the state of the Hospital in England in 1338 found the estates belonging to the commandery to be in a state of dilapidation. All the buildings needed repair. The manor needed a new roof, the bake-house was a ruin, and the manor house on the estate at Halse seems to have been a complete ruin. The Buckland estate consisted of 268 acres of arable land and 42 acres of meadow, three of the latter being held by the sisters. The commandery was under the charge of the commander Fra. John Diluwe, three chaplains, two sergeants-at-arms, one of them the steward of the sisters and a corrody. There were said to be usually fifty sisters resident at Buckland. According to the commander this proved to be a great burden on the resources of the commandery.
In 1398 the Grand Master of the Order issued special instructions for the exercise of special care in selecting a commander whose age and character should prevent any scandal arising from his association with the sisters. In due course the priory and the commandery were separated. In January 1500 at Clerkenwell it was decided to close the commandery at Buckland and let it out to farm and so a lease was granted to John Vernay at a yearly rent of £93 6s. 8d.. Vernay had to provide five chaplains on the estates of the house, one of whom was to serve the chapel of the sisters and another the chapel of the commandery.
In 1505 Buckland was endowed with the estates of four commanderies or "camerae", Kyrton, Donyngton, Toller and Chilcombe. It also received revenues from Raynham, Templcombe, Swinfield, Carbroke and a royal grant of £6 13s 4d a year. Buckland's net income amounted to £223 7s 4d a year less the £45 paid each each as responsions to the central treasury.
On 10 February 1539 the sisters gathered in the chapter house at Buckland and formally surrendered it and its endowments to the king. The prioress since 1526, Katherine Bourchier received a pension of £50 a year and pensions were awarded to thirteen other sisters as well as to their confessor
Nothing of the priory or commandery buildings survive, the only tangible remains of Mynchin Buckland are the fish ponds (vivarium).