Oliver's Battery, Tresco


Heritage Category: Scheduled Monument

List Entry Number: 1016181

Date first listed: 21-May-1963

Date of most recent amendment: 25-Sep-1997


Ordnance survey map of Oliver's Battery, Tresco
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The building or site itself may lie within the boundary of more than one authority.

District: Isles of Scilly (Unitary Authority)

Parish: Tresco

National Grid Reference: SV 89312 13497


Legacy Record - This information may be included in the List Entry Details.

Reasons for Designation

The Isles of Scilly, the westernmost of the granite masses of south west England, contain a remarkable abundance and variety of archaeological remains from over 4000 years of human activity. The remote physical setting of the islands, over 40km beyond the mainland in the approaches to the English Channel, has lent a distinctive character to those remains, producing many unusual features important for our broader understanding of the social development of early communities. Throughout the human occupation there has been a gradual submergence of the islands' land area, providing a stimulus to change in the environment and its exploitation. This process has produced evidence for responses to such change against an independent time-scale, promoting integrated studies of archaeological, environmental and linguistic aspects of the islands' settlement. The islands' archaeological remains demonstrate clearly the gradually expanding size and range of contacts of their communities. By the post- medieval period (from AD 1540), the islands occupied a nationally strategic location, resulting in an important concentration of defensive works reflecting the development of fortification methods and technology from the mid 16th to the 20th centuries. An important and unusual range of post- medieval monuments also reflects the islands' position as a formidable hazard for the nation's shipping in the western approaches. The exceptional preservation of the archaeological remains on the islands has long been recognised, producing an unusually full and detailed body of documentation, including several recent surveys. Civil War fieldworks are earthworks which were raised during military operations between 1642 and 1651 to provide temporary protection for infantry or to act as gun emplacements. The earthworks, which may have been reinforced with revetting or palisades, consist of earth and rubble platforms or banks and ditches. The Civil War fieldworks of the Isles of Scilly form a major part of the 150 surviving examples of fieldworks recorded nationally. They present an unusually complete system of fortifications from this period, both in the surviving range of fieldwork types represented and in the surviving pattern of their strategic disposition. Three main types of Civil War fieldwork have been recognised on the Isles of Scilly: breastworks, batteries and platforms; these could be deployed separately or in combination to form a defensive complex. Breastworks, which on the Isles of Scilly run beside the coastal cliff edge, consist of an earth and rubble bank, up to 4m wide and nearly 2m high but generally much smaller, usually accompanied by a ditch on the landward side. Sixteen surviving examples are recorded on the islands. Batteries are levelled areas or platforms, generally up to 20m across, situated on a hilltop or terraced into a slope to serve as gun emplacements. They vary considerably in size and shape and are usually partially or wholly enclosed by a bank, occasionally incorporating one or two outer ditches. Twenty batteries survive on the Isles of Scilly, several connected by breastworks. Adjacent to some batteries are examples of the third fieldwork type, platforms. These are partly terraced into, and partly out from, sloping ground and represent sites of lookouts and temporary buildings. Eight such platforms, measuring up to 12m by 8m in size, are known to survive on the islands. These fieldworks and fieldwork complexes were occasionally associated with other classes of defensive monument on the islands, including earthen artillery forts and blockhouses. The fieldworks were designed to defend the deep water approaches to the islands, especially St Mary's where most examples are found. Fieldworks are also known from Tresco, Bryher, Samson, St Agnes and Gugh. The circumstances of their construction are recorded in contemporary historical documents which indicate most were built by the Royalist forces which controlled the islands for the entire Civil War period except during 1646-8.

Oliver's Battery survives well, providing a good example of a mid-17th century campaign battery and one that played a pivotal role in the action to prevent a Dutch foothold in the Western Approaches and in removing the last stronghold of Royalist resistance in England at the end of the Civil War. It contains an unusual range of internal features, while its situation and the extensive records detailing its function within the overall campaign show well the strategic methods employed by military forces at this time and the role of batteries within them.


Legacy Record - This information may be included in the List Entry Details.


The monument includes an English Civil War gun battery, known as Oliver's Battery, on the southern headland of Tresco in the Isles of Scilly. Also included are two platforms accompanying the battery on the headland's east coast. The battery site also includes evidence for prehistoric activity. The gun battery is sited on a small rounded hill behind the southernmost tip of Tresco. Its interior occupies the crown of the hill and measures up to 25m ENE-WSW by up to 30m NNW-SSE, defined by a subrectangular bank along the crest of the hillslope, incorporating small outcrops on the south west and south east; on the north east it meets a massive natural outcrop that dominates the hill from that side. The interior has an uneven surface due partly to natural irregularities, with exposed bedrock behind the southern bank. The lowest, north western, area lies behind a 3.5m wide entrance gap in the north west corner of the bank. The higher south eastern corner, directly facing the island of St Mary's, is occupied by a rounded gun platform, approximately 7m in diameter, giving a distinct bulge from the line of the battery's south and east banks; the rear of the gun platform is marked off from the rest of the interior by a slight bank. In the north east corner of the interior are traces of a small rectangular building, considered to have been a store or shelter, visible as a shallow depression 6m long, NNE-SSW, by 3.5m wide in the angle of the battery's east bank with the massive outcrop to its north. The battery's earth and rubble bank is approximately 4.5m-8m wide, up to 1.3m high internally and to 4.5m high externally. From the entrance gap in its north west corner, a slight approach hollow descends the steep rocky slope to the north, flanked to its east by two short outer banks extending from the face of the large outcrop. On the east the steep hillslope drops directly from the battery bank to the coastal margin. On the south and west the bank is accompanied by a partly silted flat-bottomed outer ditch, generally 4.5m wide and 0.6m deep. The outer crest of the ditch meets a narrow flattened surface, approximately 2m-3m wide, from which the slope descends steeply into a broad trough encircling the base of the hill on the north, west and south west, defined along its outer edge by large dune formations. Although this trough is essentially a natural formation, its line is extended across the hill's lower slope around the south of the battery by an artificial ditch, generally 5.5m wide and 1m deep, obstructing approach from that direction. At the foot of the hill's eastern slope the battery is associated with two adjacent rectangular platforms, levelled up to 1.5m deep into the lower slope from the coastal edge. The northern platform measures 16m north-south by 8m wide, and the southern measures 26m north-south by 12m wide. The important role played specifically by Oliver's Battery at the end of the English Civil War is attested in historical records. Between 1648-1651, Scilly remained in Royalist control. Responding to a threat that the islands might be occupied by the Dutch, in April 1651 Parliament sent a fleet under Admiral Blake to recover control and oust the Royalist garrison, whose forces had built a defensive circuit around the main island, St Mary's. To avoid those defences, Blake initially attacked and captured Tresco. Over the following weeks, his troops built Oliver's Battery at the closest point on Tresco to St Mary's. The guns on the battery bombarded the Garrison, the military focus on St Mary's, and controlled shipping using St Mary's Pool, its chief anchorage. Working in conjunction with Blakes ship's, the battery's siege of St Mary's brought the surrender of Royalist forces on 23 May 1651. The eroding earth of the battery's southern bank has produced a quantity of pottery fragments of typical Bronze Age fabric and decoration, indicating that the battery's construction destroyed part or all of a feature of that date, considered likely to have been a funerary cairn on this distinctive hill and broadly contemporary with prehistoric settlement remains exposed on the shores to both east and west of the headland. The concrete fabric of the modern metalled road and all modern management notices are excluded from this scheduling but the ground beneath them is included.

MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 2 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation.


The contents of this record have been generated from a legacy data system.

Legacy System number: 15504

Legacy System: RSM


Books and journals
Borlase, W, Observations on Ancient and Present State of the Isles of Scilly, (1756)
O'Neil, BH St J, Ancient Monuments of the Isles of Scilly, (1949)
Ratcliffe, J, Fieldwork in Scilly 1991 and 1992, (1993)
Ratcliffe, J, Sharpe, A CAU, Fieldwork in Scilly Autumn 1990, (1991)
Ratcliffe, J, Sharpe, A CAU, Fieldwork in Scilly Autumn 1990, (1991)
Quinnell, H, 'Lighting up the Past in Scilly' in Prehistoric and Roman Pottery, (1991), 73-83
Turk, F A, 'Lighting up the Past in Scilly' in Faunal Remains, (1991), 101-106
Ordnance Survey, Ordnance Survey Record Cards for SV 81 SE 14 & 15, (1978)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7348.01, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR PRN 7347, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR PRN 7348.01, (1988)
Saunders, A D and Young, C J, AM7 scheduling documentation & mapping for SI 589, 1959, With area increased in 1979
Title: 1:2500 Ordnance Survey Map; Cornwall sheet LXXXVII: 2 Source Date: Author: Publisher: Surveyor: 1888 and 1908 editions
Title: 1:2500 Ordnance Survey Map; SV 8913 Source Date: 1980 Author: Publisher: Surveyor:
Title: Ordnance Survey Record Card for SV 81 SE 14 Source Date: 1978 Author: Publisher: Surveyor:
Title: Ordnance Survey Record Card for SV 81 SE 15 Source Date: 1978 Author: Publisher: Surveyor:
Young, C J, AM 7 & scheduling maplet for extended area of SAM SI 589, 1979,

End of official listing