Acton Burnell is best known to architectural historians for its medieval buildings – the castle and the church – built under the patronage of Robert Burnell, Bishop of Bath and Wells (circa 1239–1292). Acton Burnell Castle received a licence to crenellate in 1284 and is essentially a manor house, with fortifications for their aristocratic associations. As a structure, it is compact, with four-storey towers to each corner and possibly originally a projection at the east end, now no longer extant. The hall and solar were on the first floor at the eastern end of the main body, and are now represented by three tall, two-light cusped headed windows. An undercroft was below, with a chapel located on the first floor of the north-east tower.

The cruciform Church of St Mary, sited beside the Castle, shows a similar sophistication in its planning and details, and is clearly indebted to the same patron. The quality is impressively high, with precise mouldings and a lavish use of Purbeck marble shafts at window openings. Several features, including the trefoil headed windows of the south chancel wall, are also reminiscent of work commissioned by Burnell at Wells.

Following Robert Burnell’s death, the Acton Burnell Manor passed to various members of the Burnell family and then to the Lovells, before forfeiting to the Crown. A succession of owners followed before it was purchased, in 1617, by Humphrey Lee (d. 1632) of neighbouring Langley Hall.

Lee was granted a baronetcy in 1620 and his seat at Langley had also, like Acton Burnell, once been a Burnell possession. When Margaret, the wife of Edward Burnell died in 1377, Langley was divided, with a third of the manor passing to each of her three daughters. Of these, Joan (d. 1400) was the wife of Robert de la Lee, of Lea Hall (q.v.) and she was succeeded by her daughter, Parnel (d. 1442), wife of Robert Lee of Roden. The Lee family was able to reunite the other two-thirds of the manor of Langley by the early sixteenth century. Sir Humphry added to the gatehouse at the family’s seat at Langley Hall and also built the atmospheric chapel which remains in a field adjacent to the surviving gatehouse. Yet when he died, it was at St Mary’s Acton Burnell that he was buried, commemorated by a monument by Nicholas Stone.