London and Middlesex Archaeological Society Transactions, 66 (2015), 79—136 EXCAVATIONS IN THE NORTH- WEST CORNER OF DEAN’S YARD, WESTMINSTER ABBEY Paw B Jorgensen With contributions by Lucy Allott, Philip Armitage, Märit Gaimster, Kevin Hayward, Chris Jarrett and Kevin Rielly SUMMARY INTRODUCTION An archaeological excavation carried out in advance An archaeological excavation was undertaken of the construction of a new subterranean transformer by Pre-Construct Archaeology Ltd in advance chamber in the north-west corner of ‘the green’ in of the construction of a new subterranean Dean’s Yard, Westminster Abbey, revealed that the electrical transformer chamber in the north- earliest human activity in this naturally low-lying west corner of ‘the green’ in Dean’s Yard, area of Thorney Island was a pit dug during the Late Westminster Abbey (Fig 1), during March Iron Age or Early Roman period, which was sealed by and April 2009. Dean’s Yard is a green a build-up of alluvium. Saxon activity was evinced courtyard to the south-west of the cloisters. by two residual sherds of pottery. During the late 12th It forms part of the precinct of the former or early 13th century the process of reclamation or monastery of St Peter (commonly known as dumping to raise the ground level began and a hearth Westminster Abbey). was constructed. The bacNþll of a medieval drainage Two trenches were excavated: the main ditch contained an important assemblage of animal trench (Trench 1), which would accom- and þsh bones, providing information on aspects of modate the chamber itself, and a secondary the diet of the inhabitants of the abbey. Recovered from trench (Trench 2), for the cables connecting these reclamation dumps was a diverse assemblage of the transformer to the existing power medieval building materials, interpreted as demolition supply (Fig 2). Trench 2 followed the centre debris derived from various abbey buildings. Finds from line of the northern road around ‘the the late 16th-century dumping included a number of green’. Trench 1 was deep enough to un- tiny copper-alloy wound wire objects possibly derived cover natural deposits and was excavated from an ornate head-dress. Post-medieval features archaeologically by hand. Trench 2 was the included a 16th-century tiled path, which may have subject of a watching brief and excavated led from the kitchen to the entrance of Dean’s Yard. By by contractors to a much shallower depth the 17th century this area had been converted into a and natural deposits were only reached at gravelled yard within which was constructed a brick- its eastern end. Trench 1 was centred on lined well. The latest signiþcant feature was a 1th- National Grid Reference TQ 2997 7941 century culvert or sewer. and covered approximately 64m2. Trench 2 covered an area of approximately 50m2. The site archive will be deposited with the Westminster Abbey Museum under the Museum of London site code DYR09. 79 80 Paw B. Jorgensen Fig 1. Site location, showing the approximate extent of Thorney Island as deþned by the 1.m 2D contour of the underlying natural sand and gravel scale 112, DRIFT GEOLOGY AND TOPOGRAPHY containing infrequent patches of decayed organic material, which lay at a maximum The site was located near the western edge height of +0.92m OD. At the eastern end of what was historically Thorney Island, of Trench 2 (some 40m east of Trench 1), the largest and probably the highest of the natural sandy gravel was observed at a height islands within the Tyburn delta. It is likely of 2.92m OD. that the island was formed some time during the Neolithic period by the deposition of ARCHAEOLOGICAL AND sand and gravel between two branches of HISTORICAL BACKGROUND the Tyburn River at their conÿuence with the River Thames (Thomas et al 2006, 9—10). There have been a number of archaeological In Trench 1 the top of the natural sequence investigations within the vicinity of Dean’s (Phase 1) was recorded at +0.92m OD in the Yard. The redevelopment of 20 Dean’s Yard west from where it sloped down to +0.64m (Fig 2) in 1975—7 allowed archaeological OD in the east. The natural deposits at Dean’s investigations which included the excavation Yard comprised waterlain layers of coarse of part of the sub-vault of the Abbey sand, [157], at -0.01m OD and +0.64m OD, Misericorde (Black 1976; 1977). In 1986 divided by a 0.24m-thick horizontal band of small-scale excavations were undertaken mid-yellowish grey clay, which occurred at a within the Dorter undercroft which revealed maximum height of +0.40m OD (Fig 3). This 11th-century alluvial silts, a later 11th-century sequence was sealed by an alluvial deposit of road, a possible precinct ditch, a substantial grey to greenish brown clayey sand showing timber structure and 12th- and 16th-century signs of occasional root disturbance and usage of the undercroft (Mills 1995) (WST86 Excavations in the North-West Corner of Dean’s Yard, Westminster Abbey 81 Fig 2. Trench location, also showing other archaeological investigations in the vicinity scale 112 on Fig 2). In 1998—9 an archaeological features including a ditch inþlled during investigation at 17 Dean’s Yard (Fig 2) the 11th—12th centuries (Jorgensen 2008; revealed Middle and Late Saxon alluvial Maloney & Holroyd 2009, 80—1) (TSA08 on deposits overlain by medieval reclamation Fig 2). In 2010—11 a watching brief on the dumps (Murray 2003). More recently in 2008 replacement of a gas main in Dean’s Yard a watching brief at the Sanctuary to the north itself and the Sanctuary revealed medieval of Dean’s Yard revealed various medieval and post-medieval building remains (Boyer 82 Paw B. Jorgensen 2011; Wylie 2011, 42). Excavations within in the immediate vicinity. In addition to the Cellarium in 2011—12 uncovered the this, residual sherds of pottery dating to this previously investigated Misericorde together period were discovered below the Dorter with Saxon and medieval deposits and undercroft (Mills 1995), and have been features including possibly part of the 10th- found recently at the Cellarium (C Jarrett, century monastery (Jorgensen in prep; pers comm). Maloney 2012) (WYA10 on Fig 2). The discovery of the Middle Saxon royal Based on the results of earlier investigations hall nearby and the evidence for occupation it appears that during the Late Neolithic on the island itself during this time may and the Early Bronze Age arable farming indicate the presence of a minster church, was carried out on Thorney Island. Then although structural remains relating to this due to rising water levels, human activity are yet to be found (Cowie & Blackmore along the periphery of the island probably 2008, 99). However, reliable documentary ceased, although transient usage of the evidence for the founding of a church on higher parts of the eyot continued into the the island does not occur until the reign Iron Age (Thomas et al 2006, 31). It has been of King Edgar when it is reported that estimated that the water levels had reached St Dunstan, Bishop of London and later a height of above OD by the Early Iron Age Archbishop of Canterbury (AD 960—88), and continued to rise to approximately either founded or refounded the church as +1.00m OD during the Early Roman period. a Benedictine monastery between c.AD 958 The water subsequently receded to a level and c.AD 961 (Brooks 1992, 22). According of c.+0.50m OD. This would have restricted to the anonymous author of Vita Ædwardi occupation during the Roman period to Regis the monastic community on Thorney those areas of the island located above Island, by the reign of Edward the Confessor approximately 1.00m OD, namely the areas (1042—66), comprised a small group of occupied by the abbey buildings (Sloane et impoverished monks living in dilapidated al 1995, 362). buildings surrounding St Dunstan’s church Even though the higher parts of the (Barlow 1970, 229). island could have been occupied during the After Edward the Confessor ascended the Roman period there is no direct archaeo- throne a programme of works was initiated logical evidence for this. Virtually every to rebuild the dilapidated monastery on a archaeological investigation conducted in grand scale. Work on a new church in the the vicinity has recorded residual Roman Romanesque style started and by the time of þnds. One possible explanation for the Edward’s death work on the rebuilding of the lack of Roman features is that the deposits ancillary structures was under way, although belonging to this period have been erased by the church had not yet been completed. By erosion caused by episodic ÿooding during the close of the 11th century the refectory, the early medieval period (Thomas et al kitchens, dorter and reredorter had been 2006, 149—50). completed. Throughout the 12th century It has been suggested that Thorney Island work on the church and cloisters continued. was home to a small Middle Saxon monast- It is likely that the western towers of the ery. This suggestion has been based on church were added during this time (Tatton- the existence of a charter of doubtful Brown 1995, 174—5). This century also saw authenticity recording a land grant made in the construction of the inþrmary and St AD 785 by King Offa of Mercia to St Peter’s of Katherine’s Chapel, both to the south-east Westminster (Mason 1988, 321; Sawyer 1968, of the great cloister (Thomas et al 2006, 56). no. 124). However, the nearby discovery The next major building phase was at the site of the Old Treasury Building in initiated by Henry III and ultimately led Whitehall of a high-status (possibly royal) to the destruction of much of Edward’s hall, dated from the late 8th to mid-9th Romanesque church.