Headstone Manor, Harrow, Middlesex: Archaeological Watching Brief and Excavation within the Moated Island, 2016-17 & Headstone Manor, Harrow, Middlesex: Archaeological Watching Brief and Excavation in the Outer Court, 2016-17

Between November 2016 and July 2017 Oxford Archaeology conducted a
programme of archaeological works, consisting of watching briefs and limited
excavations, during the repair and refurbishment of the Scheduled Monument of
Headstone Manor, Harrow, Middlesex (centred NGR 514090 189710).
Within the moated enclosure a building of flint-and-chalk block walls bonded with a
coarse yellow sandy lime mortar was uncovered just outside the standing Manor
House on the north-west. This structure, which was aligned north-east to south-west
parallel to the standing manor, was 7.6m wide and at least 16.8m long, running
underneath the north-east extension believed to be of 18th-century date. The walls
were built free-standing, and were progressively encased by nearly 1m of
redeposited clay. A construction horizon including flint chips showed that the walls
had been dressed during the dumping of the redeposited clay. This construction
sequence is the same as that used for the cross-wall and hall of 14th-century date.
The building had one cross-wall and shorter walls within the south-west room
dividing up the perimeter, and a pitched tile fireplace in the angle between one of
these short internal walls and the south-east wall. The floor of the building appears
to have been the surface of the clay used to build up the interior, and as well as
reddening around the fireplace, several other areas of burning were found across
the building, covered by dark charcoal-rich deposits, suggesting other fireplaces or
hearths. Environmental samples from the deposits around the pitched tile hearth
included charred cereals and peas, fish bones and a wide range of small mammal
bones. Charcoal from two successive occupation deposits, the later one overlying
the tile fireplace, were radiocarbon-dated to 1298-1410 cal AD and 1430-1475 cal
AD, confirming the medieval date of this building. The burning and charcoal spreads
may indicate that the south-west room was used as a kitchen, and had a period of
abandonment before it was demolished.
To the south of the Manor House's hall, a series of flint walls, all bonded with a
similar mortar, were uncovered during landscaping works. These walls, which were
only 0.25m below ground, were built in two phases, the first probably representing
the outline of the medieval domestic accommodation range south-west of the hall. In
the second phase the south-east end of this block was reduced in size, and a stonelined
garderobe pit built against the new end wall. An open drain cut through the
south-east corner of the earlier building, and the finds from this, together with those
from the garderobe pit, suggest that this was used in the later 16th century.
Beyond the medieval accommodation range, two parallel walls may indicate a long
narrow building continuing south-east. This was probably of post-medieval date, as
it had only shallow flint foundations, and the superstructure is likely to have been
timber-framed. Several more flint-and-chalk block walls were found in service
trenches just east of the moat bridge. Possible alignments roughly at right angles to
the moat, and parallel to it, can tentatively be suggested, but the remains were
fragmentary. This may, however, represent the remains of a former gatehouse. The
extent of redeposited clay found suggests that most of the moat platform was raised
by up to 1.15m, probably with clay from the construction of the moat, but possibly
also from local quarries, which may be the origins of some of the ponds shown on
historic maps along the south and west sides of the Outer Court.
&
Between May 2016 and July 2017 Oxford Archaeology conducted a programme of
archaeological works, consisting of watching briefs and limited excavations, during
the repair and refurbishment of the Scheduled Monument at Headstone Manor,
Harrow, Greater London (NGR 514090 189710).
The current access road through the Outer Court, and areas of the current courtyard
to either side, proved to overlie a cobbled/metalled surface of mid-19th century date
laid directly on the natural clay geology, indicating that here the ground had been
truncated (ie cleared of topsoil) prior to its deposition. In places, this had also
truncated much of the stratigraphy of earlier buildings within the court, but both
structural evidence and sequences of earlier deposits survived over most of the
area.
The corner of a flint-and-mortar-built structure was found at the north-eastern end of
the Great Barn, whose robbing contained pottery of late medieval date. This may
either represent a structure of this date, or may belong to an earlier version of the
Great Barn constructed in 1506, which some historic maps suggest was previously
wider than at present.
Structures of post-medieval date include a brick floor and wall edge built with 17thearly
18th-century bricks north-west of the Granary, and a wall of 18th-century
bricks south of the Great Barn towards its north-east end. The flint-and-brick walls
and rammed chalk floors belonging to a late 18th/early 19th-century east-west barn
were found on the southern edge of the Outer Court, and match a building shown on
historic maps from 1819 to 1916. A brick floor and walls belonging to a building
south of the Small Barn were also uncovered, and although not directly dated, these
match a building shown on the 1819 sale map. Immediately outside the Small Barn,
a porch marked on the 1st edition OS map of 1865, and surviving until the early
20th century, was also found.
Chalk and pebble surfaces were uncovered to the south of the Great Barn, one
overlain by flint walls incorporating bricks flanking wooden planks, forming a
walkway up to the south-west porch, while a raised flint-and-chalk roadway was
found in line with the north-east porch. The remains of a chalk-and-clay-built ramp
leading up to the western end of the bridge over the moat was also recorded.
An infilled channel or pond up to 11m wide was found south-west of the Small Barn
in two trenches, showing that it was orientated south-westward to north-east. Within
it, several vertical timbers set into postholes were found along the north edge, and a
felling date of 1709-10 was obtained from one of these uprights, but it is uncertain
whether this timber was original, or was inserted at a later date. A bank of
compacted chalk encased in clay and flints ran south-eastwards, appearing to divide
the channel or pond into two. This bank had a line of angled timber uprights along
the south-west side and vertical uprights on the north-west edge, with planks
aligned south-east within the body of the bank. These were presumably revetting.
On the north-east side (towards the moat) the bank was abutted by a series of
sloping deposits suggestive of deliberate infill. The earliest of these contained brick
and tile fragments dated to the late 17th or 18th century, and surrounded a further line of smaller upright timbers. Further dumping on the north-east had completely
infilled the channel by the late 18th century, when it was recut, but the recut appears
to have been filled in soon after, and had completely gone by the early 19th century.
On the south-west side of the bank the channel deposits were not well-dated, but it
had clearly gone out of use by the time the maps of 1817 and 1819 were drawn.
This structure may have been an earlier example of the series of large ponds shown
on historic maps outside the south corner of the Outer Court until the later 19th
century. These ponds may have resulted from clay quarrying around the edges of
the Outer Court, but may also have been linked to the moat and the ponds further
west, acting as an overflow channel from the moat in times of flooding, and being
part of the water management system linking the moat to the Yeading Brook.
North of the Small Barn on the east side of the Outer Court, broad cuts or hollows in
the natural of similar date may indicate further ponds, but as these were not
bottomed, may instead represent areas of the farmyard churned by animals.