A few prehistoric flint flakes were found north of Touchbridge Farm and from the inclusion of a microlith among them, it is thought that they may be Mesolithic in date. There is a little evidence for Roman activity in Boarstall parish. Roman pottery and tile has been found in a field north-west of Boarstall Wood and in one south of Boarstall Tower where there is now a golf course. Roman metalworking slag and pottery has been found in a field south-west of Touchbridge Farm and it is thought the ironstone for smelting came from Muswell Hill.
Boarstall was part of Bernwood Forest. Bernwood had been a hunting forest from the time of Edward the Confessor. It grew to its largest extent under Henry II. The whole area was not covered by woods; in the medieval period a forest was a place where deer roamed for hunting and so included open land, villages and fields. All those who lived in the forest were not allowed to hunt or even gather wood without a special licence from the king. Bernwood Forest was finally disafforested in the reign of James I in 1635, although it had been shrinking in size since the time of King John (1199-1216). Boarstall Manor was part of the royal manor of Brill until 1213 or perhaps later. The core of the manor was 'Derehyde', a piece of land belonging to the chief warder of the forest.
All that is left of Boarstall Manor now is the tower of the gate-house and part of the moat. There are also records of a licence to crenellate (construct battlements for) the manor house in the 14th century. This is when the gate-house tower and moat were constructed. The Boarstall Cartulary of 1444 shows the manor house and gate-house. Dendrochronological dating of the timbers of the ground floor ceiling joists shows that they were cut down in 1312-1313. The beams in the roof, however, were felled in 1614-1615, suggesting the roof was redone when the parapet was raised. The manor house itself dated back to the 12th century originally, but it was demolished in the late 18th century. Geophysical survey has located the foundations and some yard surfaces of the manor house.
The village has mostly disappeared as well, apart from a few farmhouses. The only marks of smaller houses are the confused jumble of earthworks in nearby fields to the north, west and south. The village was depicted in the plan of 1444 as well. This shows the church and village with open fields of ridge-and-furrow surrounded by the trees of Bernwood Forest. The fields were enclosed by 1697. The commander of the Royalist garrison at Boarstall destroyed the village and the church in 1645 during the Civil War. The commander of Boarstall, Sir William Campion, waited until after the third siege to knock down the houses, when it became clear that they were a threat to the defenders. He did not destroy the manor house, however, as that is depicted on a picture of 1695. This print also records the formal gardens, traces of which were found in a recent geophysical survey but the present layout dates to 1925.
One of the other medieval things that Boarstall is famous for is the pottery industry. There is a 15th century record to a 'Potterisplace' in Boarstall. Brill/Boarstall Ware is common around north Buckinghamshire and Oxfordshire and the location of several kilns has been pinpointed. Several may be south of Boarstall Tower across the road towards Honeyburge and others across the road to the east. Still more pottery wasters have been found south-west and north-east of Manor Farm and the pits where the clay was dug seem to be south of the farm. A possible bank of a town boundary has been identified in the same field, suggesting that the kilns were on the edge of the settlement.
St James' church is recorded from the 12th century but is thought to have been destroyed in the Civil War, even though there is a small church on the print of 1695. The present church was built on the same spot in 1818. There are records that Painshill Farm was also surrounded by a moat, but this cannot now be seen. There is another moat to the east of Boarstall Tower that is in a field called Bardell's or Bardall's. This may be connected with a mention of Bardolphys Garden in a document of 1449. There is another possible moat at New Park Farm. These moats may be the sites of other large houses in Boarstall parish in the medieval period.
Boarstall Duck Decoy remained in use trapping ducks until the late 1950s, although it had become quite silted up in the 19th century. It is first noted in maps of 1697 and 1788. It was restored from 1968 and is now a nature reserve managed by the National Trust.