Reasons for Designation
Motte and bailey castles are medieval fortifications introduced into Britain
by the Normans. They comprised a large conical mound of earth or rubble, the
motte, surmounted by a palisade and a stone or timber tower. In a majority of
examples an embanked enclosure containing additional buildings, the bailey,
adjoined the motte. Motte castles and motte-and-bailey castles acted as
garrison forts during offensive military operations, as strongholds, and, in
many cases, as aristocratic residences and as centres of local or royal
administration. Built in towns, villages and open countryside, motte and
bailey castles generally occupied strategic positions dominating their
immediate locality and, as a result, are the most visually impressive
monuments of the early post-Conquest period surviving in the modern landscape.
Over 600 motte castles or motte-and-bailey castles are recorded nationally,
with examples known from most regions. As one of a restricted range of
recognised early post-Conquest monuments, they are particularly important for
the study of Norman Britain and the development of the feudal system. Although
many were occupied for only a short period of time, motte castles continued to
be built and occupied from the 11th to the 13th centuries, after which they
were superseded by other types of castle.
The motte at Thurleigh is of unusual form, having a top platform on two
levels, and is thought to retain well-preserved building remains. The bailey
is also of unusual form and is exceptionally large and therefore likely to
contain evidence for the identification of areas devoted to different
activities (such as accommodation, service quarters, stores and granaries,
stock-management enclosures, even possibly gardens and arable fields). The
presence of water-filled features may enable recovery of environmental data by
which contemporary and later economic usage of the bailey area can be
reconstructed.
Details
The monument includes a motte and bailey castle and three ponds situated to
the south east of Thurleigh parish church, on land which falls towards the
Ravensden Brook, a minor tributary of the River Great Ouse. The motte lies at
the north of the bailey, adjacent to the churchyard, and comprises an earthen
mound which is oval in plan, measuring 60m long by up to 40m wide at its base.
The top of the motte is between 40m long by 20m wide and is on two levels,
being higher at its north-eastern end which is thought to have held the
stronghold. At its highest point the motte is about 7m above the bottom of the
surrounding ditch which varies in width between 7m and 30m and is up to 2.5m
deep at the north and shallower at the south where it holds standing water.
The north-western edge of the ditch is strengthened by an outer bank 5m wide
by up to 1m high which has been slightly altered in places by the insertion of
later property boundaries. To the south of the motte is an extensive bailey
which is irregular in shape and measures 200m north-south by 270m east-west.
Although the northern perimeter is thought to have been destroyed by various
activities within the curtilage of properties adjacent to High Street and the
remainder has been partially altered by its incorporation into later field
boundaries, the location and form of the defences is recorded on a survey of
1904. The south-western arm of the defences lie at the foot of the natural
slope. An 8m wide outer bank which appears on the 1904 survey has since been
ploughed flat but the ditch within it remains as a field drain 4m wide by 1.5m
deep which carries the Ravensden Brook. Two large ponds, which are thought to
have been constructed by enlarging an original inner ditch, lie within the
outer ditch or stream bed. A 20m wide causeway carrying a farm track now runs
between the two ponds but they were originally continuous. The northern pond,
known as `Black Pond', measures 115m long by 18m wide and is silted up. The
southern pond, `Westminster Pond', is separated from the outer ditch by a
slight bank 5m wide. This pond is 120m long by 25m wide, with a small island
of 10m by 4m in the middle it holds deep well-aerated water. About 30m
beyond the southern end of Westminster Pond, the line of the bailey defences
turns through 90 degrees to run up the slope on a north-easterly alignment.
The first 120m of this southern arm is not apparent at the surface but its
bank is recorded on the 1904 survey and an outer ditch is thought to survive
as a buried feature; the remaining 170m is incorporated into the modern field
boundary as a partially infilled ditch and slight bank beneath the hedge. The
1904 survey depicts the earthworks extending for 60m into the grounds of the
Old Vicarage but this area was built over in the late 1970's and the
earthworks destroyed; excavations in advance of development revealed that
little of the Norman castle remained but finds indicated that the site had
been occupied in the Iron-Age, Roman and Saxon periods. Although the interior
is under arable cultivation and contains buildings and hardstandings
associated with Bury Farm, deeper-cut medieval features relating to the use of
the bailey survive below ground, especially towards the bottom of the slope
where the accumulation of hillwash favours the survival of archaeological
deposits. This is confirmed by fragments of building stone having been found
in the ploughsoil. Three ponds shown on the 1904 survey are now infilled but a
fourth, located 20m south-east of the motte, remains as an open feature. The
pond is irregular in outline with a ramp leading into it from the west. It
measures a maximum of 30m by 15m and is up to 2m deep; it is seasonally water-
filled.
The motte and bailey has been identified as the easternmost of a postulated
line of defensive sites on the upper reaches of the Ouse which extends to
Odell. The building of the castle has been ascribed to King Stephen (1135-54).
The standing buildings, boundary walls, fences and the made surfaces of
trackways and hardstandings are excluded from the scheduling but the ground
beneath is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
