About three miles south-west of Thame, off the A329, lies an enchanting medieval chapel that speaks of a spirituality strange to modern faith. Rising like a pocket-size parish church from its patch of greensward, Rycote recalls a time when lords and ladies employed other people to sing for their souls.

During the Middle Ages, nobles built chapels where prayers could be said on their behalf. And mass could be celebrated there daily whether the family was in residence or not to fuel their hopes of salvation.

One such is Rycote. Richard Quatremaine founded the chapel, which was consecrated in 1449, not long before the outbreak of the Wars of the Roses. An Oxfordshire man of some wealth and influence, he was a councillor both of the Duke of York and of his son, King Edward IV.

To the chapel he attached three priests, one of whom seems to have lived in the tower. Climb the narrow, winding stair today and you can still see the little priest's room, with its fireplace, under the belfry.

There must have been lodging elsewhere for the other two clerics, probably a chantry house leading off the north wall of the chancel, where a small doorway survives.

The merits of Cotswold stone were already well known in medieval times, and stone from the Taynton quarries, near Burford, was brought to Rycote for the building work.

However, in Richard's day the chapel would have been more ornate, with an opulent sanctuary screened off to enclose a panel painting, embroidered altar frontal and silver candlesticks.

But if the richer medieval furnishings are missing, the magnificent 15th century wagon roof survives (partly repaired in the 1960s), with almost all the original seating in the nave.

The simple backed benches with their rectangular ends were the work of rural craftsmen and are intensely atmospheric.

Oddly, within a pew against the north wall, there is a little fireplace whose flue and chimney are contained in one of the buttresses. Possibly, this was an oven for baking wafers for the mass; such features are occasionally seen elsewhere.

The chapel was well known to Elizabeth I. In her youth, when she detained at Woodstock during the reign of her sister Mary, she came more than once to Rycote.

The house was owned by Sir John Williams, a courtier of great eminence, who had been appointed one of her guardians. He managed to stay in royal favour through the turbulent reigns of Henry VIII, Edward VI and Mary.

The captive Elizabeth had some affection for Sir John; he treated her with a kindliness and tact denied to her by others employed to watch over her, and she became very friendly with Sir John's daughter, Margery.

Elizabeth's friend, Robert Dudley, Earl of Leicester, introduced Margery to Henry Norreys and they were married in 1560.

Besides having personal memories for Elizabeth, Rycote was also conveniently placed en route between London and Oxford. When Elizabeth became Queen, she would return many times to Rycote as guest of Margery and Henry Norreys.

On her last visit in September 1592, she brought her whole court and was entertained by sweete musicke' in the garden.

To her that day were brought letters and gifts from four sons of the Norreys family, all serving her majesty abroad one in Ireland, one in Flanders and two in Brittany.

The Norreys boys were a brood of spirited, martial men' according to a contemporary report. Of six sons, five were to die on active service.

The family evidently built the Norreys Pew, a sumptuous canopied affair of about 1610 in the north of the chapel nave, with a minstrels' gallery above it.

This is among the glories of the chapel, and might have been stage-set for some romantic pageant. Another, slightly later canopied pew rises from the other side of the nave, and was probably built for a visit by Charles I.

He came to Rycote in 1625, during the first summer of his reign, when an outbreak of the plague in London drove Parliament to Oxford.

And the ill-fated monarch would return to Rycote in 1643 and 1644, when he was governing his beleaguered realm from Oxford during the Civil War.

In due course, Rycote descended to the Bertie family who were earls of Abingdon. They added the chapel's elaborate, baroque reredos, the wooden screen at the back of the altar. In their time also appeared the black and white chequer-work floor, and four lozenge-shaped memorial stones, delightfully inscribed.

As for the great house itself, very little survives. In October 1745, fire destroyed part of the building, and the ten-year-old heir, James Bertie, died in the blaze. The house was rebuilt by Withoughby, the 3rd Earl, and modernised with sash windows replacing the Tudor mullions.

Capability Brown worked at Rycote for 20 years re-landscaping the park and extending the medieval fishponds to form the 13-acre serpentine Rycote Lake in 1760.

The 4th Earl was 20 when he succeeded and by the time he died, 39 years later, his fortune had gone. His son Montague, the 5th Earl, demolished the great house in 1807 and turned the Tudor diaper-brick guest quarters and domestic offices, together with the earlier stables, into a shooting lodge and manor house.

By an irony, 19th-century neglect of the property ensured the chapel's intact survival. No harm was ever done by Victorian improvers'. The manor was sold by the seventh Earl in 1911, and in 1936, the architect Goodhart Rendell added a small wing. Further restoration work has been carried out by the present owners since 2000.

Outside the chapel looms a venerable yew tree, over 26ft in diameter, which is said to have been planted at the coronation of King Stephen in 1135 which would make it centuries older than the chapel itself.

The building's attendant told me on my visit that goldcrests were nesting in the tree, and indeed, the bird life at Rycote seemed remarkably rich. A green woodpecker flew ahead of my car as I approached by the drive. A red kite hovered over the car park; a cuckoo sang in the distance; pheasants moved through the little wood behind the building. Rycote Chapel lies on the leafy Oxfordshire Way, a lowland path linking the Cotswolds with the Thames via the Chilterns. From the wood you can walk all the way to Thame, whose parish church of St Mary the Virgin contains important memorials to Rycote notables.

Dominating the chancel is the splendid tomb of Sir John Williams and his first wife Elizabeth Bledlow, wrought in marble with alabaster effigies, greyhound and unicorn at their feet.

In the south transept is the earlier table-top tomb' of Rycote Chapel's founder, Richard Quatremaine, with his wife Sybil. The brass shows Richard in armour, with a massive elbowpiece characteristic of his time. A third figure on the tomb is Richard Fowler, possibly a godson. When the couple died childless, he became heir to Rycote.

Nearby is an even earlier table tomb, commemorating ancestral Quatremaines who died in the 14th century. This tomb was formerly known as the Poor Stone' because coins would be placed on it for distribution to the needy.

The church and its embellishments were damaged and desecrated during the Civil War, but the tombs survive in testament to families who besides developing Rycote were great benefactors of Thame itself.

Cared for until recently by English Heritage, Rycote Chapel is now owned by Mr and Mrs Bernard Taylor and managed by the Rycote Buildings Charitable Foundation.

It is open until September 30; Friday, Saturday and Sunday, 2-6pm. However, it may close at short notice for services and events. Call 01844 210210 for details.