In 1261, Edmund, Earl of Lancaster, second son of King Henry III, granted Down Ampney to Sir Nicholas de Valers, a Templar knight who actually fought in the last Crusade, He and other Knights Templar founded the church in 1260. When Templars were suppressed by the crown in 1315, the church passed to the Abbey of Cirencester, who retained it until the Dissolution of the Monasteries, after which it passed again to Christ's Church College, Oxford. Much of the current shape of the church is the result of a Victorian rebuilding. The striking spire dates to the 14th century, when the south porch was added.
In the south transept are a pair of effigies, partly shielded by a lovely canopied niche. The first is that of Sir Nicholas de Valers, who died about 1300. He is enveloped in a complete suit of chain mail, as worn at the end of the 13th century. A hauberk, which covers the body from the neck to the middle of the thighs, where it is cut up, has long sleeves extended to cover the hand like a muffler. A hood of mail protects the head and shoulders, and a narrow strap round the temples keeps it in place. Chausses of mail cover the legs and feet, with straps buckled on the instep and passing under the foot, but no spurs are attached; at the knees are small poleyns, probably of cuir bouilli. Over all is worn a long flowing surcoat, cut open below, and so full about the waist that the cingulum is hidden. Buckled across the hips is a very broad sword-belt, barred at intervals for the buckle tongue, which hangs straight down, and ends in a studded scape, the long end being passed twice round the scabbard of a cross-hilt sword. Borne upright, and low on the left arm, is a heater shield charged with the de Valers arms: "On a cross ,5 escallops "; it is fastened to a broad guige buckled on the breast, and passing over the right shoulder disappears beneath the hood of mail. He is in the act of sheathing the sword, the right hand on the pommel, whilst the left appearing from under the shield steadies the scabbard. His head rests on a large oblong pillow; feet pressed against a lion couchant, holding the end of the sword in its mouth. A low plain stone tomb supports the effigy and slab. There is no inscription.
A slab of Purbeck marble, let into the floor at the side of this monument, bears an inscription. It was read by Lysons to contain the name (Xicho)las de Villers—XXXIII., and by Mr. St. Clair Baddeley (1907) (Margar)eta de Valers— MC(CC)XVI. The latter is known to be the daughter of Sir Nicholas, and was lady of the manor of Down Ampney in 1316.
The second effigy, on a raised tomb, is placed within a recess under a high ogee arch of the early 14th century, cusped and decorated with a border of ball flowers, and ending in a beautiful floriated finial. At each side is a moulded pillar, ending in a tabernacled pinnacle. The front of the tomb is decorated with quatrefoils within diamonds. It is of an unknown lady, perhaps of the Nicholas' daughter and heir of Down Ampney, Margaret. The lady wears a long kirtl to the feet, with tight sleeves and over it a sleeveless cote-hardie with large slits at the sides for the arms, though not large enough for it to be called "sideless"; it falls in full folds to the feet. From the shoulders hangs a long mantle, fastened across the breast by a drooping cordon. The neck and chin are covered with a wimple drawn up on either side of the face to the ears, and, there slightly distended to show the hair. A plain veil falls over the forehead and backwards to the shoulders. The shape of the feet in pointed shoes is seen beneath the kirtle. The hands are raised in prayer. Her head rests on two pillows, the under one oblong and tasselled, the upper square and set diagonally. Her feet rest on a dog lying down with a tufted tail. A low plain stone tomb supports the effigy and slab. There is no inscription.

HUNGERFORD CHAPEL
The north transept, or Hungerford Chapel, is enclosed within a fine oak screen. Part of the screen is made from the Musician's Gallery at Cirencester Abbey. The fragments were rather fortuitously found in a yard in Down Ampney parish and moved into the church. Within the chapel is a grandiose memorial to Sir James Hungerford and his son Anthony, successive lords of the manor and owners of Down Ampney House. The gilded, ornate monument dates to 1637, and shows father and son facing each other across a prayer desk in a typically pious pose. One rather obvious element missing from the memorial is any sign of Sir James's wife, Anthony's mother. Directly opposite the memorial, rather lost in the shadows of the west wall, is a small brass plaque to Mary Berkeley, James Hungerford's first wife.