CITY GATE HOUSE, 39-45 FINSBURY SQUARE, LONDON EC2 LB ISLINGTON ARCHAEOLOGICAL DESK-BASED ASSESSMENT Prepared for BSREP II City Gate Ltd Mills Whipp Projects, 40, Bowling Green Lane, London EC1R 0NE 020 7415 7000 [email protected] January 2019 CITY GATE HOUSE, 39-45 FINSBURY SQUARE, LONDON EC2 Summary The purpose of this report is to identify the archaeological potential of deposits on a site at City Gate House, 39-45 Finsbury Square EC2 in LB Islington and consider the scheme’s likely impact on them. The roughly square site is centred on National Grid Reference TQ 3287 8185 and is approximately 3600 sq m (Fig. 1). During the preparation of this report the Greater London Historic Environment Record (HER) was consulted for an area of 250m radius centred on the proposed development (Historic England report No.14597) (Fig. 2). The subject site but does not contain any Scheduled Ancient Monuments and does not lie within a Designated Archaeological Area as defined in Scheduled Ancient Monuments & Archaeological Areas Act 1979. It does, however, lie within an Archaeological Priority Area as defined by LB Islington. The research indicates that there is a low potential for significant prehistoric, Roman, Saxon, mediaeval or post mediaeval archaeology on the site. The proposed groundworks are minimal. It is suggested that if forthcoming geotechnical investigations fail to reveal significant archaeological deposits then the development is permitted to proceed without archaeological constraints. CITY GATE HOUSE, 39-45 FINSBURY SQUARE, LONDON EC2 ARCHAEOLOGICAL DESK-BASED ASSESSMENT Contents 1. Introduction 2. Geology and Topography 3. Prehistoric 4. Roman 5. Saxon and Mediaeval 6. Post Mediaeval 7. Archaeological Potential 8. Impact Assessment 9. Conclusions Appendix 1 Archaeological Gazetteer Appendix 2 Sources Consulted Appendix 3 Planning Background Fig.1 Site Location Fig.2 Archaeological Background Fig. 3 Wyngaerde 1544 Fig.4 Copperplate Map 1553 Fig.5 Agas 1562 Fig.6 Braun & Hogenberg 1572 Fig.7 Faithorne & Newcourt 1658 Fig.8 Moorfields 1665 Fig.9 Morgan 1677 Fig.10 Rocque 1746 Fig.11 Horwood 1799 Fig.12 Ordnance Survey 1873 Fig.13 Ordnance Survey 1894 Fig.14 Ordnance Survey 1913 Fig.15 LCC Bomb Map 1945 Fig.16 Ordnance Survey 1970 Fig.17 Existing Foundations and Proposed Trial Pit Fig.18 Proposed Section CITY GATE HOUSE, 39-45 FINSBURY SQUARE, LONDON EC2 1. INTRODUCTION 1.1 Mills Whipp Projects has been commissioned by BSREP II City Gate Ltd to prepare an archaeological desk-based assessment of site at City Gate House, 39-45 Finsbury Square EC2 (Fig.1). 1.2 The subject site is centred on TQ 3287 8185 on the south side of Finsbury Square. Lackington Street lies on the southern boundary. It lies within an Archaeological Priority Area as defined by LB Islington advised by the Greater London Archaeological Advisory Service (GLAAS), part of Historic England. 1.3 The Greater London Historic Environment Record (HER) has been consulted for an area 250m radius centred on the site with relevant data drawn from a wider area (GLHER Report 14597). The chief cartographic sources have been used and a selection of these is appended as figures. Printed primary and secondary sources for the history of the area have been employed, and research undertaken in the London Metropolitan Archive and London Library. 1.4 A site inspection was carried out by Mills Whipp Projects on 18th January 2019. 1.5 Dates used in this report: Palaeolithic c 700,000–8,000 BC Mesolithic c 8,000–4000 BC Neolithic c 4000–2000 BC Bronze Age c 2000–600 BC Iron Age c 600 BC–43 AD Roman 43–410 Saxon 410–c 1000 Mediaeval c 1000–1500 Post mediaeval–modern (1500–present) Author PM 23.1.19 Checked By MH 23.1.19 Revision Finssqgaterep2 Version 2 Finssqcitygaterep2 2. GEOLOGY and TOPOGRAPHY 2.1 The subject site lies on the on the northern side of the River Thames on the upper part of the valley side. In this area the geology consists progressively of older Pleistocene and Eocene beds outcropping down the riverbank. Basal geology is composed of London Clay buried beneath drift deposits formed of Pleistocene (Quaternary) fluvial sediments deposited by the early River Thames (British Geological Survey, 1:50 000 Series, sheet 256). These deposits are arranged in flights or gravel terraces representing the remains of former Thames floodplains, the highest (most northerly) being the oldest with each terrace becoming progressively younger down the valley side. 2.2 Deposit modelling by the British Geological Survey (BGS) specifies two gravel terraces within this part of southwest Islington. The older Hackney Gravel lies on the northern side of the site while the younger Taplow Gravel lies beneath the site. Discrete areas of both gravels are shown capped by a sandy silt brickearth (Langley Silt) which formed in the Late Devensian stage (32,000-10,000BC). It is considered to be a combination of loess and water lain sediments and was an important source of building material in London in all periods. That closest to the site is shown to lie approximately 400m to the west. Just west of the site the survey indicates that the gravel gives way allowing the basal London Clay beneath to outcrop in two relatively small areas. 2.3 Archaeological interventions within the study area have been used to refine the BGS model. Excavations at 127-139 Finsbury Pavement in 1996 to the west of the site (site code: FIS96) recorded brickearth at 12.28m OD and Taplow Gravel at 11.33m OD (MoLA, 2009, 11). Brickearth was also recorded in 1998 at 50 Finsbury Square (site code: FSQ98). It lay at 11.73m OD but was truncated so it too is likely to have originally lain at over 12m OD (MoLA, 2009, 19). It capped the Taplow Gravel. These interventions show that in the immediate vicinity of the site the Taplow Gravel has a brickearth cap which lies at an elevation of over 12m OD. 2.4 The older Hackney Gravel was recorded during several archaeological excavations. At 25-32 Chiswell Street, approximately 120m to west it was recorded at 14.40m OD (site code: CSU96) (MoLA, 2009, 26). At Bunhill Row, approximately 400m north- west of the site, the gravel was recorded at 16.50m OD capped with brickearth at 17.10m OD (site code: BRV98). This indicates that the brickearth cap is widespread in southwest Islington. 2.5 The brickearth sloped down from the western side of Finsbury Pavement to the east and south. At 119-125 Finsbury Pavement west of the site, truncated brickearth lay at 11.30m OD (Gaz.ref.9, Birbeck 1990 16). Approximately 100m to the east at 31-35 Wilson Street it lay at 10.87m OD (Gaz.ref23, Norton 1994 27) while excavations at 10-13 Dominion Street revealed the truncated brickearth at 11.18m OD (Gaz.ref.4, Mackie 1988 i). 2.6 Brickearth is likely to be the highest natural deposit on the site probably at an elevation of approximately 11.50m OD to 12.00m OD i.e. roughly 3m to 4m below the existing pavement. The brickearth geology can attract early settlement as it is well drained and produces lighter soils. It is also a useful building material and was quarried throughout this area from the Roman period onwards. A mediaeval brickearth quarry was recorded at 50 Finsbury Square (MoLA, 2009, 19). 2.7 On the site the modern ground level slopes down from the north at c.16.50m OD to the south at c.15m OD reflecting vestiges of the historical topography of the area, although heavily masked by later levelling within the Walbrook headwaters. Excavations and observations of the drift geology in the immediate vicinity of the site are hampered by the generally deep, modern basements in this part of Moorfields, most removing the brickearth cap and the upper portion of the terrace gravel so altering the original topography. Nevertheless, brickearth and gravel has been recorded at the following elevations during interventions in the immediate vicinity of the site. Maximum elevations have been used: 25-32 Chiswell Street brickearth 14.47m OD; gravel 14.40m OD (Gaz.ref.3) 119-125 Finsbury Pavement truncated brickearth lay at 11.30m OD (Gaz.ref.9) 127-139 Finsbury Pavement brickearth 12.28m OD (Gaz.ref.10) 50 Finsbury Square brickearth 11.73m OD (Gaz.ref.13) 25 Ropemaker Street gravel 14.47m OD (Gaz.ref.16) 2.8 Topography shaped the early settlement pattern, mainly because of its influence on soil quality and the availability of fresh water. In this case the location of the subject site on the terrace gravels is characterized by numerous small streams rising from springs further north and draining southwards into the Thames. The area was dominated by the River Walbrook; a dendritic stream system which rose in the Shoreditch area from numerous sources, gradually combining to discharge near Cannon Street station. Its main channel lay south of Finsbury Circus. The stream’s numerous shallow valleys gave rise to marshy valleys cutting the gravels which resulted in a ridged topography of gravel bars. 2.9 Chiswell Street, approximately 100m west of the site, may follow the line of one such bar which may have formed a natural crossing of the marshy area; it may have provided access to the mediaeval manor house Finsbury Court. The name ‘Chiswell’ is derived from OE ceosol meaning flint, pebble (EPNS 1942 93, 97). 2.10 The data generally shows the natural slope southwards towards the Thames as would be expected. At Bunhill Row, approximately 500m north-west of the site the gravel was measured at 16.50m OD while by the site it is recorded at 14.40m OD and at Finsbury Circus to the south at 10.20m to 7.60m OD (Gaz.