place. Andrew Morrison, also from the Yorkshire Museum,more recently gave assistance and permission to publishthe York examples. Thanks also go to the Thomas LaytonTrust for permission to publish their ingots. Thediscussion about Syagrius would not have been possible

without the kind advice of Roger Tomlin, and JustineBayley, as ever, freely offered advice about vessel metalcomposition. Last but no means least, I would like to thankNick Griffiths for the drawings and Jon Cotton and JustineBayley for commenting on the draft.

Introduction

Entry A31 in the London Museum’s Accession Register(1912) reads as follows: ‘‘Hoard’ composed of eightcopper ingots and six fragments. Late Celtic period.Found together in Kingsway. Bought.’

The attribution to the ‘Late Celtic period’ – possiblysupplied by G F Lawrence through whose hands the ingotscould well have passed (eg Sheppard 1991, 47–8) – hascaused this curious find to languish virtually unnoticedwithin the prehistoric holdings of the Museum of Londonfor a century. Its recognition and reappraisal here is, as sooften, the result of simple serendipity: a combination of anopen cupboard and the chance presence of two curatorsresponsible for entirely separate period collections. JohnClark noticed them and commented that they were morelikely to be early medieval than prehistoric. This study istherefore presented to him to show how a combination of

documentary research and scientific investigation supportshis curatorial hunch.

Description of objects

The group of as-cast ingots (Fig 1) comprises 15 pieces,two of them complete bar ingots, one broken butcomplete example, and 11 fragments from up to ninefurther ingots; their total weight is just over 2.5kg. Theirsimilar appearance and dimensions (Table 1) suggest that they were made at one time and place. Their cross-sections vary from V-shaped to U-shaped with more thanone profile visible in a single ingot (Fig 2). The convexupper surfaces and the chill marks (‘wrinkles’) on themshow the ingots are ‘as-cast’. This is confirmed by theirundistorted dendritic structure (see Fig 3a, below). Themolten metal was poured from one end, which is usuallyless well-defined than the further end which is invariably

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A SAXON BRASS BAR INGOT CACHE FROM KINGSWAY, LONDON

Justine Bayley, Jonathan Cotton, Thilo Rehren and Ernst Pernicka

Fig 1 The ingots from Kingsway, MOL Accnos, left to right: A31/10, A31/5b (above),A31/2b (below), A31/7a, A31/5a, A31/6,A31/4, A31/1, A31/3, A31/2a, A31/8,A31/7b (above), A31/9 (below), A31/11,A31/12 (photograph John Chase). © MOL

rounded. Theophilus, writing in the early 12th century,describes making coarse brass: ‘... remove one crucible ...and pour out everything into [little] furrows cut in theground’ (Hawthorne & Smith 1979, 144), an action that would have produced ingots just like those fromKingsway.

The surfaces of the ingots are corroded, showing avariety of brown and green colours, and this corrosioncontinues across the broken ends. X-radiographs of theingots show most have some porosity and/or inclusions,most marked in areas that appear to be overflows from thegrooves in which the bars were cast, probably the last metaladded to the bars. These areas may contain some slag thatwould have derived from the crucible in which the metalwas melted. In a few cases the bar ingot has obviously beendeliberately bent, and this has resulted in the metalfracturing; no nicks or other tool marks to start the breakare visible. The X-radiographs also show widespreadcorrosion of the metal which preferentially follows physicalinhomogeneities. On a smaller scale the corrosionattacked the more copper-rich cores of the dendrites (Fig3a), and in some cases it has penetrated the whole wayacross the bar. This corrosion is the result of a lengthyperiod of burial in an aggressive environment and mayhave led to some of the fractures, perhaps explaining whythere are now more fragments than were purchased in1912.

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MOL Acc no. Description Dimensions (mm) Weight (g)

A31/1 Complete ingot with up-turned distal end; the proximal end appears to have 370 x 16 x 12 366

broken away from the source of the molten metal.

A31/2 Complete ingot (now in two pieces as a result of a ‘recent’ break). Both ends 352 x 16 x 10 328

rounded, the proximal end rather irregular in form. (280+48)

A31/3 Nearly complete ingot, up-turned rounded distal end present. 305 x 15 x 10 292

A31/4 Complete ingot, up-turned rounded and slightly dished distal end present; the 332 x 14 x 9 298

proximal end either bent or down-turned and covered in concretion mixed

with ?charcoal.

A31/5 Nearly complete ingot (in two pieces), both ends missing. 306 x 16 x 10 292

(235+57)

A31/6 Substantial portion of ingot with both ends missing. Slightly bent and cracked 267 x 16 x 10 257

towards one end.

A31/7 Substantial portion of deliberately bent ingot (in two pieces). Both ends missing. 237 x 18 x 10 243

(198+45)

A31/8 Substantial portion of ingot (proximal end missing). 253 x 17 x 11 259

A31/9 Deliberately bent ingot fragment with rounded distal end. 101 x 18 x 9 78

A31/10 Slightly bent ingot fragment with rounded distal end. 82 x 16 x 8 51

A31/11 Ingot fragment with rounded distal end. The old break appears to incorporate 86 x 15 x 10 72

a number of charcoal flecks.

A31/12 Small segment of ingot. 44 x 15 x 10 40

Table 1 Details of the Kingsway Saxon bar ingots. Note: the metal was poured from the proximal end and flowed towards the distal end ofthe ingot

Fig 2 Drawing of one ofthe ingots, length 352mm(MOL Acc no. A31/2;drawn by Nick Griffiths)

The findspot

At first sight the provenance ‘Kingsway’ gives as muchpause for thought as the attribution to the ‘Late Celtic’period, though further reflection suggests that there islittle reason to doubt its veracity. For Kingsway lies beyondthe west bank of the Fleet and is thus well outside theboundary of the Roman and medieval cities in an areathen (pre-1912) largely bereft of finds. Anyone seeking toenhance the interest (and market value) of the objectswould surely have attached a more saleable provenance,such as somewhere in the City. There is good evidence thatsuch contemporary chicanery was commonplace (eg Hugo1860; Marsh 1979). However, as the ingots are, inthemselves, visually unappealing objects, even theattachment of a suitably enticing provenance was unlikelyto have significantly enhanced their monetary value.

All things considered therefore we can be reasonablyconfident in accepting that the cache was indeedrecovered from Kingsway. Furthermore, the presence

of fragments suggests that it is likely to be complete andthis, combined with the unusual provenance, mightindicate that the find was made only shortly prior to itspurchase and accession by the London Museum in 1912.Precisely where along Kingsway it was found is less easy to determine of course, although we can narrow thesearch a little by examining the nature of the area’sredevelopment.

Kingsway was the result of a late Victorian programmeof slum clearance begun in 1889 and designed to improvetraffic flow between Holborn and the Strand. Conceived in1892, the road was laid out as a 100-foot (30.5m) wide tree-lined boulevard between two much older and narrowernorth-south routes, Drury Lane to the west, and ChanceryLane to the east. It was officially opened by Edward VII in1905, in whose honour it was named (Bradley & Pevsner2003, 351; Weinreb et al 2008, 465–6). Once completed, thefrontages of the new thoroughfare were leased tospeculative builders with the intention of creating a newcommercial district (Ross & Clark 2008, 234). The building

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123

a

b Fig 3 Optical images of the section removed fromingot MOL Acc no. A31/9. © Thilo Rehrena) The top edge of the ingot. When molten brassfreezes the first metal to solidify is copper-rich. Theremaining metal, which contains relatively morezinc, fills the gaps between the dendritic (branching)crystals. Here the cores of the dendrites havecorroded preferentially, leaving a porous surfacestructure. There is no distortion of the dendrites,showing that the ingot is as-cast and has not beenworked (hammered). Image width c. 4mm.b) The un-corroded core of the ingot. Between thebrass dendrites are inclusions of copper arsenide(blue-grey) and zinc sulphide (black). The brassmust be newly-made as the zinc sulphide would notsurvive re-melting. Image width c. 1mm.

plots were only slowly taken up, however, with constructionwork carrying on intermittently well into the 1920s.

Many of the largest buildings were erected after 1912,which helpfully rules them out of consideration aspotential provenances for our ingot cache. Sir JohnBurnet’s Kodak House (no. 63) on the west side of theroad midway between the Strand and Holborn appearsmost relevant; it was completed in 1911, the yearimmediately preceding the accession of the ingot cache. Ifwe accept the suggestion made above that the cache wasnewly found, then the site of Kodak House is a strongpotential candidate for its original findspot.

Irrespective of where along Kingsway the cache wasoriginally from, it is clear that the findspot must have lainsomewhere close to the eastern boundary of middle-SaxonLundenwic, at least as currently understood (Fig 4; eg Cowie& Blackmore 2012, fig 1). Other stray finds of Middle/LateSaxon date from this same general locality include ‘goldenearwires from the Aldwych’ (Vulliamy 1930, 232; Cowie1988, 44, no. 55); a sherd of Ipswich-type ware withimpressed decoration from ‘Kingsway/Gate Street’purchased in December 1919 (MOL Acc no. A21049; ibid,43, no. 42); and an annular fired clay loomweight found ‘inthe Kingsway in January 1920’ (MOL Acc no. A21088; ibid,44, no. 56). Further finds from the immediate localityinclude fragments of a Roman fine ware bowl, and aRoman brooch of Polden Hill type, together with a numberof post-medieval objects. The absence of any significantnumber of either Roman or medieval finds from the areamakes a Saxon date for the ingots the most likely option.

The composition of the metal

The first question was the nature of the copper alloy.Surface X-ray fluorescence (XRF) analysis showed all the

ingots were brasses (copper-zinc alloys) containing minoramounts of arsenic, but demonstrated they were toocorroded for this data to provide more than a generalindication of alloy type. The identification of brass (seebelow) reinforces the potentially middle to late Saxon datesuggested by the hoard’s findspot.

To determine the exact chemical composition of theingots small samples were cut from them. Semi-quantitative XRF analyses of the cut and polished metalsamples showed the brass contained large amounts of zinc(well over 20%) and percentage levels of arsenic, as well asminor amounts of lead but no detectable tin or antimony.Subsequently small uncorroded areas of the samples wereanalysed by microprobe, the results being calibratedagainst those for metal standards of known composition.The three samples chosen for lead isotope analysis (LIA)(A31/3, A31/5 and A31/12) were also analysed using amore sensitive XRF system (Lutz & Pernicka 1996); theseresults generally agreed with the microprobe results andadditionally provided data for traces of nickel andantimony. The analytical data is given in Table 2.

The probe analyses confirm that all the samples arezinc-rich brasses without any further deliberately-addedalloying components such as tin or lead. Minor amounts ofarsenic and lead are universally present, mostly in therange 1–2% and 0.2–0.5% respectively. Metallographicexamination showed that in addition to the expectedstructure of an as-cast two-phase brass (Fig 3, a–b) thereare inclusions of both zinc sulphide and an intermetalliccopper arsenide with a composition close to Cu3As (withsome zinc and antimony) between the dendrites in almostall ingots (Fig 3b).

The brass was almost certainly produced by thecementation process, by which copper metal is heated withzinc carbonates or oxides under reducing conditions

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Fig 4 Location maps showing: a) The probable findspot of the ingots (1) lies on the north-eastern edge of Lundenwic; b) Placesmentioned in the text

(Bayley 1998); speltering, the fusion of metallic zinc andcopper, is a post-medieval development and as suchunlikely for our ingots. During cementation, practiced inboth the Roman and medieval periods, metallic zincvapour is produced and diffuses into the copper, changingit into brass. The presence of zinc sulphide inclusions arean indicator of newly-made brass as they would be oxidisedand disappear if the alloy was remelted. The virtualabsence of tin and the low levels of lead also suggest thatthis is fresh brass and not recycled metal.

Parallels

A group of 25 complete brass bar ingots, two-thirds the sizeof those from Kingsway are known from the Viking town ofHaithabu in Jutland (Roesdahl & Wilson 1992, 252), while

fragments and shorter bar ingots are known from Viking-age Dublin (Bayley in prep) where all but a few of the 20that have been analysed are brass. The four fragments from10th- or 11th-century contexts in York (Bayley 1992a) were arange of different copper alloys, but included one of brasswhile the four fragments from Lincoln with similar dates areall zinc-rich alloys (Bayley 2008, table 32). The few othercopper alloy bar ingot fragments from controlledexcavations in England include a brass one from Ipswichand an impure copper one from Canterbury, both fromearly medieval contexts (Bayley 1992b). The PortableAntiquities Scheme (PAS) database lists 26 copper-alloy baringots or fragments but the largest is only 80mm long andmost are far smaller. Sixteen of these pieces are not as-castas they have at least some hammer marks; three of thesehave been published (Geake 2001, 242). The majority of

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Samples Cu Zn As Pb Fe Ag S Ni Sn Sb Au Total

MOL Acc no.

A31/8* - 28.0 1.32 0.15 0.08 0.07 - 0.08 0.04 0.04 tr -

A31/10 71.5 26.8 1.17 0.33 0.24 0.03 0.08 nd nd nd nd 100.2

A31/12 71.8 24.3 2.00 0.43 0.11 0.05 0.05 0.03 nd 0.15 nd 98.7

A31/1* - 24.0 2.88 0.20 0.06 nd - nd 0.02 1.05 nd -

A31/6 72.7 22.7 1.46 0.27 0.04 0.04 0.09 nd nd nd nd 97.4

A31/2 75.5 22.5 0.90 0.03 0.07 0.04 0.08 nd nd nd nd 99.2

A31/3 75.0 22.1 1.71 0.33 0.05 0.04 0.11 0.03 nd 0.10 nd 99.4

A31/7 73.7 22.0 1.75 0.27 0.05 0.04 0.07 nd nd nd nd 97.9

A31/9 75.2 22.0 1.67 0.48 0.05 0.04 0.02 nd nd nd nd 99.5

A31/5 74.8 21.9 1.33 0.20 0.05 0.04 0.23 0.04 nd 0.13 nd 98.5

A31/11 76.2 19.6 1.26 0.07 0.03 0.03 0.08 nd nd nd nd 97.3

Standards Cu Zn As Pb Fe Ag S Ni Sn Bi Total

42.23.2 74.36 22.13 0.168 0.575 0.354 0.045 0.168 1.63 0.034 99.5

74.32 21.88 0.18 0.60 0.38 0.01 0.08 0.17 1.79 0.04 99.5

50.01.4 74.08 1.17 0.22 11.74 0.243 0.113 2.24 9.45 0.029 99.3

76.6 0.56 0.00 9.41 0.14 0.00 0.23 1.20 11.97 0.11 100.2

50.04.4 76.11 0.66 0.06 9.94 0.10 0.14 1.10 11.30 0.10 99.5

73.87 1.11 0.12 12.48 0.30 0.00 0.23 2.43 10.12 0.06 100.7

71.32.4 80.48 6.52 0.25 4.43 0.35 0.034 0.08 0.70 6.46 0.051 99.4

80.47 6.38 0.19 4.36 0.42 0.01 0.14 0.75 6.67 0.07 99.4

Keynd = not detected; tr = trace; - = no data; * = previous microprobe analyses by Peter Northover; Cu = Copper; Zn = Zinc; As = Arsenic; Pb = Lead; Fe = Iron; Ag = Silver; S = Sulphur; Ni = Nickel; Sn = Tin; Sb = Antimony; Au = Gold; Bi = Bismuth; Co = Cobalt; Te = Tellurium

Bi, Co, Te were sought by microprobe but were not detected in the samples. The values quoted for Ni and Sb for samples A31/3, A31/5 and A31/12 weredetermined by XRF.

The makers of metal standards certify their composition (these figures are shown above in italics). The standards were analysed twice, at the same time asthe samples from the ingots. The mean value (in roman) shows good agreement with the certified values, demonstrating the accuracy of the data from theingot samples.

Note: No sample from A31/4 was analysed

Table 2 Chemical composition of the ingots ordered by zinc content (wt%)

the PAS finds are attributed to the early medieval periodbecause silver bar ingots of similar form are found in hoardstogether with coins of that date. However, on their own, baringots are intrinsically undatable, though alloyidentification of these finds might help pin them down.

A number of fragmentary bar ingots have beenrecovered from sites in the City of London. For ourpurposes, the most useful group are those from VintryHouse (VRY89) on the London waterfront (Schofield &Maloney 1998, 298). Six of the eleven complete andfragmentary as-cast bar ingots that have been analysedwere recovered from stratified contexts, principally dumpsbehind or over wooden revetments, one of which has beendated by dendrochronology to between 984 and 1063(Robin Wroe-Brown pers comm). All but one of theseingots were brasses though zinc contents were mainly farlower than for the Kingsway ingots (Bayley 2010). Manycontained significant amounts of lead (median >2%) andonly two had detectable but low arsenic contents (<0.5%).All the complete examples are far shorter than those fromKingsway and most have smaller cross-sections.

There are two Continental finds of bar ingots known tous, similar in form to those from Kingsway, which havebeen dated to the Roman period; fragments are alsoknown (Kuhnen & Bunk 2003). A bundle of about twelveimpure copper bar ingots was found on a mosaic floor inTrier, together with a pierced early-3rd-century coin (ibid).The total weight of the hoard was about 8kg, withindividual ingots weighing up to 730g; the largest ingotwas 370mm long, 30mm wide and 18mm thick; all havelarger cross sections than those from Kingsway (Table 1).The second group, of over 50 ingots, came from the Rhinenear Mainz and are a good match for the size of theKingsway ingots; many of them were acquired by theMittelrheinisches Landesmuseum in 1891. A few havebeen analysed and have varied compositions: impurecopper, high-tin bronze and gunmetal with about 10%zinc. These are dated to the Roman period on the basis oftheir compositions (Bachmann & Jockenhövel 1974).

Still further afield is the remarkable 2 tonne cache ofmore than 2000 brass bar-ingots from the MauretanianSahara at Ma’aden Ijâfen (Monod 1969) with associated14C dates of 1024–1329 and 980–1303 cal AD (Garenne-Marot & Mille 2007, 168). 1 These are thought to havearrived via one of the caravan routes from the north – anoccurrence that opens up more questions than can beaddressed here, though intriguingly their metallographicstructure (Monod 1969, 308), chemical (Werner & Willett1975, table 7) and lead isotope composition (Joel et al1995) are very similar to those of the Kingsway ingots;further research is underway.

The origin of the metal

The identification of the ingots as brass raised thequestion of where the metal might have come from, as

there is no known evidence of copper mining or brassmaking in Britain in the early medieval period (Bayley et al2008, 51; Bayley 1998, 20), even though objects made ofbrass become common from the Middle Saxon periodonwards (Bayley et al 2008, 50, fig 65). When consideringthe source(s) of the brass there are two possible scenarios.The first involves smelting copper ores at one location andtransporting the metal to another place where zinc oreswere mined and the copper was turned into brass. Thealternative is that the copper was smelted and turned intobrass at a single location, requiring that both copper andzinc ores were available there. Both these scenarios assumethat the ores were smelted or used near where they weremined, a practice that was normal until post-medievaltimes. The ingots produced would have been widely tradedacross Europe and beyond (see above).

We consider the most likely source area to beContinental Europe, and in particular what is nowGermany and its surroundings. There are well-documented Roman and/or later medieval lead, zincand/or copper mines in the Eifel and adjacent areas to the east of the Rhine in north-west Germany, further southin the area around Heidelberg, and especially to the eastand south-east in the Harz and Erzgebirge mountains.There is now increasing evidence (eg Rehren et al 1993;Hildebrandt 1997) that some of these areas were beingworked from the 10th century if not earlier. Various areasof the Alps were also exploited for their ores from theBronze Age onwards, though the low nickelconcentrations in the ingots preclude most of the Alpinecopper deposits (Christoforidis & Pernicka 1988; Pernickaet al 2008; Lutz et al 2010).

In order to identify the geographical region(s) wherethe brass used to make the ingots could have beenproduced, lead isotope analysis (LIA) was undertaken. Allores contain varying proportions of different lead isotopesdepending on the type and geological age of the oredeposit, regardless of whether it is a lead ore or whetherthe lead is just an impurity. When an ore is smelted, mostof the lead is transferred into the metal. Measuring theamounts of the different lead isotopes present in a metalsample allows their ratios to be calculated, which can thenbe compared with data from known ore sources. In thecase of brass, however, a major problem is that bothcopper and zinc ores can contain similar amounts of lead,so the lead isotope data may reflect the isotope ratios ofthe lead in one or other of these elements, or of a mixtureof both.

Analyses of later medieval copper ingots from CentralEurope show lead concentrations at the levels seen in theKingsway ingots (Rehren 1995), and experimental brasscementation, using technically pure copper and lead-containing natural calamine, resulted in an alloycontaining around 2 wt% lead (David Bourgarit perscomm) – more than four times the amount seen in ouringots. Thus, the lead content is most likely a mixture of

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lead from both the copper and the zinc ores.Samples from three of the ingots were analysed. The

results are given in Table 3 and first of all show that theingots cannot have been cast from the same meltingcharge as they have significantly different lead isotoperatios.

One well-known zinc source is that to the west of thelower Rhine which has been exploited and used for theproduction of brass since the Roman period (Davies 1935;Rehren 1999). Significantly, this is also the region with theearliest medieval evidence for brass making, dated tobefore c. 800, in Dortmund (Rehren et al 1993). Theresults of the lead isotope measurements were thereforefirst compared with those of the major lead-zinc depositsin western Germany. Only the sample from A31/5, the onewith the lowest lead content, is compatible with lead-zincores from the Eifel region and also possibly those from theSiegerland, although it is not clear if mining can beattested there in the early medieval period. SampleA31/12 is only marginally compatible with these oredeposits and sample A31/3 not at all (Fig 5).

A further possible source is Wiesloch, near Heidelbergin the middle Rhine. The lead-zinc ores were exploited by the Romans and are known as a source of silver as early as the 12th century (Hildebrandt 1997). It is ofparticular interest as the ore here is known to be arsenic-rich and has been used for copper and brass making fromat least the later medieval period onwards, with much ofthe early evidence destroyed by later mining activity.However, this mineralization can definitely be ruled out asa source for the ingots based on the lead isotope evidence(Fig 5).

The Kingsway samples all plot within the English andWelsh lead isotope outline (as defined by Rohl &Needham 1998), so a British source cannot be ruled outon the basis of the LIA, even though it is consideredunlikely due to the lack of evidence for early medievalcopper smelting or brass cementation. However, arsenic-rich copper ores are not common in the British Isles andthose that are known also contain elevated levels ofantimony and silver (Ixer & Budd 1998). Thus, the higharsenic but low silver content of the ingots effectivelyexcludes a British source.

So, where else could one look? Although it is generallyassumed that mining in the Harz Mountains only began in the 11th century, it is becoming increasingly clear thatthis is true only of silver production, and mining forcopper actually began earlier (Brockner & Klappauf1993). Since minor element composition and the leadisotope data for all three ingots are reasonably consistentwith ores from the Harz region, especially those of theRammelsberg and some lead-zinc ore veins in the westernHarz (Fig 6), and since brass was produced there on aregular basis from late medieval times on and shippedalong the Elbe river for export, this seems at present to bethe best guess for the provenance of the metal of the threeingots.

Discussion

The LIA have suggested a possible source area for the oresthat were smelted to make the ingot metal, but it isimportant to remember that while it is a good techniquefor ruling out source areas, as has been done for north-west Germany, it cannot prove that metal came from aparticular source, only that it could have come from that

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Table 3 Lead isotope ratios of the samples with their individual 2σ confidence limits

Lab no. MOL Acc no. 208Pb/206Pb 207Pb/206Pb 206Pb/204Pb Pb (wt%)

MA-100967 A31/3 2.1040 ± 0.0001 0.86038 ± 0.00001 18.104 ± 0.001 0.33

MA-100968 A31/5 2.0886 ± 0.0001 0.85296 ± 0.00001 18.284 ± 0.003 0.20

MA-100969 A31/12 2.0987 ± 0.0001 0.85843 ± 0.00003 18.140 ± 0.005 0.43

Fig 5 Lead isotope ratios of the analysed samples compared withmajor lead-zinc deposits in western Germany. Data for theGerman deposits are from Schneider (1994), Brauns (1995),Krahn (1988), Durali-Müller et al (2007). © Ernst Pernicka,Justine Bayley

source. If we are right in assigning a German source to theingots, they were probably brought to London as part ofthe trade from northern Germany – either down theRhine or Elbe rivers.

Turning to evidence for brass making, the earlyevidence from Dortmund has already been mentioned.The Dortmund Adlerturm crucibles have volumes of 75ccand 200/230cc respectively (Rehren et al 1993) – thelarger ones for cementation, smaller ones probably formelting together the fresh metal. Recent experiments haveshown that even cementation in large crucibles oftenproduces only small volumes of brass (Bourgarit &Thomas 2011, fig 10). So pouring metal made in cruciblessimilar to the larger ones from Dortmund direct into ingotfurrows would be a good match for the effective volume ofthe Kingsway ingots which weigh around 400g, equivalentto c. 50cc of metal.

The spread of lead isotope ratios found is consistentwith this scale of ingot production, as it suggests that theingots were cast individually from relatively small cruciblecharges, as described by Theophilus (Hawthorne & Smith1979, 144; Rehren et al 1993), and not from the largermore homogenous batches that were produced in the latemedieval and early Renaissance periods (Martinón-Torres& Rehren 2002).

The presence of the ingots in the Kingsway area,especially broken fragments, provides evidence for localmetalworking. There is other Middle Saxon evidence fromLundenwic (eg Malcolm et al 2003, 271–8; Cowie &Blackmore 2012, 160–3), and Late Saxon finds from the

City (Bayley et al 1991; Keily 2002, 35). That this valuablecache of metal was not found in the centre of thecontemporary settlement is perhaps not surprising; itwould have been easier to hide in a less-frequented area.

Conclusion

The general form of the Kingsway ingots can be paralleledfrom late Roman to Viking times, and throughout themedieval period, and on its own cannot be used for datingthem. The widespread use of this very basic form shouldnot come as a surprise as it is a practical one that allowssmaller pieces to be easily detached for remelting orwrought fabrication. The composition of these bar ingots,however, changes with time, reflecting the alloys in use. Itis the fresh nature of the alloy, indicated by the sulphideinclusions and the virtual absence of tin, its relatively highzinc content, and the spread in lead isotope ratios thatsuggest an early medieval date for the Kingsway ingots, andtheir archaeological context narrows this date further tomid or possibly late Saxon. The uniformity of form andalloy show they are likely to have reached their findspot asa single group, probably from a single workshop. The LIAsuggests this could have been located in the Harz area ofnorthern Germany, an area renowned for copper workingfrom at least the 12th century (Brandt 2008), though thevaried results show the lead in the alloy comes from twodifferent sources – most likely the copper and the zincores used to produce the brass.

We hope this study has shown the potential of metalingots to illuminate questions of trade and metalworkingpractice and will encourage further study of the increasingnumbers of visually similar ingots now being found.

Acknowledgements

Thanks are due to Karla Graham for taking the X-radiographs, to Peter Northover for providing the resultsof his unpublished analyses of ingots A31/1 and A31/8,and to Philip Connolly (EPMA), Nicole Lockhoff andBernd Höppner (XRF, LIA) for carrying out some of therecent analyses. David Bourgarit is thanked forunpublished information concerning his experimentalbrass making, and for suggesting Wiesloch as a potentialsource of arsenic-rich brass. Thanks are also due to BenoîtMille for drawing our attention to the bar ingots fromMa’den Ijâfen; to Robin Wroe-Brown (MOLA) forsupplying information regarding the contexts of the ingotfragments recovered from Vintry House in the City ofLondon; to Nick Griffiths for Figure 2 and to JuditPeresztegi for Figure 4.

NOTES1 I-2769, 785 ± 110 BP; Dak-I, 860 ± 108 BP.

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Fig 6 Lead isotope ratios of the analysed samples compared withthose for lead ores from the Harz region in northern Germany.Data for places labelled: 1) from Lévêque & Haack 1993; 2) fromWedepohl et al 1978; 3) from Höhndorf & Dill 1986. © ErnstPernicka, Justine Bayley

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