CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND TO THE STUDY

Iron is among the most consequential materials in human history. Once societies learned to extract the metal from its ores and to forge it into tools and weapons, the effects were felt in agriculture, warfare, trade, craft specialisation, ritual life and political authority. Iron axes and hoes made it easier to clear woodland and open farmland, while iron weapons altered the balance of power between communities. For this reason, the study of early iron production is more than a technical exercise. It is a way of understanding how past societies organised labour, exploited their landscapes, and attached meaning to the technologies on which they depended (Childs & Killick, 1993; Holl, 2000; Chirikure, 2015).

In sub-Saharan Africa, the study of early ironworking has long been bound up with a single question: where and when did the technology originate? For much of the twentieth century the dominant view held that iron smelting was introduced into the region from the Mediterranean world or the Nile valley. Radiocarbon dating changed the terms of this debate. Reviews such as that of Miller and Van Der Merwe (1994) brought together dates from West, Central and East Africa which suggested that smelting south of the Sahara was not necessarily younger than in the supposed source areas. Not every early claim has survived scrutiny. Killick et al. (1988), for example, re-examined the evidence from the Agadez region of Niger and showed that many structures dated to before 1000 BC consisted of partially vitrified soil that could not be positively linked to a metallurgical process. Other claims have been more durable, and Holl (2009) argued that the accumulating data from West and Central Africa could no longer be set aside in favour of the older orthodoxy. More recently, Killick (2015) has argued that African iron smelters were inventive, even though very low population densities limited innovations in mass production and transport, while Chirikure (2015) has stressed that African metallurgical traditions must be understood within their own social, cultural and ecological settings.

Nigeria occupies a central place in this discussion. In the central part of the country, the furnaces excavated at Taruga and associated with the Nok culture have long served as a reference point for early iron smelting in West Africa; a radiocarbon determination of 2230 ± 120 BP from Taruga is among the dates frequently cited (Calvocoressi & David, 1979; Tylecote, 1975). Newer research on Nok iron production has since added furnace sites and technological detail to this picture (Junius, 2023). In the south-east, the Nsukka area of northern Igboland has produced an equally important body of evidence. Okafor and Phillips (1992) published new radiocarbon ages from Nsukka that bore directly on the question of the origins of African metallurgy, and Okafor's (1992, 1993) analysis of slags and residues led to a three-phase technological sequence for the area, which is discussed in Section 1.7.6. Smelting sites such as Opi, Orba, Umundu, Aku, Obimo, Owerre-Elu, Nru and Ukehe have been investigated in the Nsukka zone (Daniel et al., 2022; Daraojimba et al., 2022). Elsewhere in Nigeria, a recently investigated smelting site at Ile-Ife in the south-west has been dated to the thirteenth to fifteenth centuries AD (Oni et al., 2022), a much later horizon, which illustrates how long and varied the history of iron production within the country was.

Within the Nsukka area, Lejja is of particular importance. Lejja is a cluster of 33 villages in Nsukka Local Government Area of Enugu State, where iron smelting was carried out on a large scale (Eze-Uzomaka et al., 2024). Slag, furnace walls, haematite and tuyère fragments are abundant across its hills and valleys, and the scale, distribution and diversity of these remains indicate that smelting was practised on an industrial scale over a long period (Eze-Uzomaka et al., 2024). The most visible expression of this industry is in the village square of Otobo Dunuoka, where more than 800 cylindrical slag blocks, each weighing between about 34 and 57 kg, have been arranged and preserved (Eze-Uzomaka, 2013; Eze-Uzomaka et al., 2024). The blocks survive in part because of their durability and in part because of traditional taboos against tampering with them or removing them from the square (Eze-Uzomaka, 2013). Dunuoka is also the only village that produces the Eze (king) of Lejja, so that the slag-block square is at once an industrial relic, a political space and a ceremonial centre (Agu & Opata, 2012; Eze-Uzomaka et al., 2024). Iron smelting itself is now extinct in Lejja, and there are no active iron smiths in the community (Eze-Uzomaka, 2013).

Archaeological interest in Lejja is not new. Anozie (1979) published the first widely cited account of early iron technology at Lejja and Umundu. Okafor's work on slags and residues established the technological sequence for the wider Nsukka area (Okafor, 1992, 1993; Okafor & Phillips, 1992; Whiteman & Okafor, 2003). Excavation and survey at Dunuoka in 2007, carried out jointly by archaeologists from the University of Nigeria, Nsukka and the University of Dar es Salaam, were followed by further excavation at Amaovoko (Eze-Uzomaka, 2007, 2009, 2010; Chami et al., 2011). Radiocarbon determinations from Lejja include dates as old as 4005 ± 40 BP and 3445 ± 40 BP, which would place smelting in the third and second millennia BC, as well as younger dates of 2050 ± 40 BP and 1715 ± 35 BP that fall closer to the early-phase dates known elsewhere in the Nsukka area (Eze-Uzomaka, 2009, 2010; Eze-Uzomaka et al., 2024). Geophysical work using the magnetic method has been used to locate buried furnaces, slag blocks, blooms, tuyères and fired pits in selected Lejja villages (Ogah, 2013). More recently, archaeobotanical research has examined the relationship between farming and ironworking at Lejja (Ngonadi, 2023), and two seasons of systematic survey in 2017 and 2018 identified sixteen new sites in thirteen villages, which were grouped into smelting, domestic and ancestral sites (Eze-Uzomaka et al., 2024).

Taken together, this body of work establishes Lejja as one of the most significant iron-smelting landscapes in Nigeria and a key reference point in the wider debate on the antiquity of African metallurgy. Yet the same literature also shows that much remains to be resolved. Eze-Uzomaka et al. (2024) themselves note that earlier surveys at Lejja were highly limited and largely unpublished, that little is known about the communities that practised the industry beyond the technologies they employed, and that the chronology of the sites remains sparse. It is against this background that the present study undertakes an archaeological investigation of early iron smelting activities at Lejja, with the aim of documenting the physical evidence of smelting, clarifying the technology and chronology of the industry, and situating it within its social and environmental setting.

1.2 STATEMENT OF THE PROBLEM

Despite its reputation, the early iron smelting industry of Lejja remains incompletely understood, and several interrelated problems justify the present investigation.

The first problem is chronological. The radiocarbon determinations reported from Lejja are widely cited, but they do not agree with one another. The oldest dates, 4005 ± 40 BP and 3445 ± 40 BP, are regarded by Eze-Uzomaka et al. (2024) as controversial and somewhat contested, although they cannot be ruled out, while the dates of 2050 ± 40 BP and 1715 ± 35 BP seem more consistent with the early phase of smelting that clusters around or just over 2000 BP in the Nsukka area. The authors also observe that the chronological picture is thin because of the small number of dates and the small number of sites from which they come. Until the dates are placed in clear stratigraphic and technological context, claims about the antiquity of iron smelting at Lejja will continue to be debated, and the site's contribution to the African origins question will remain uncertain.

The second problem concerns technology. The three-phase sequence for Nsukka proposed by Okafor (1993) was built largely from the study of slags and residues and applies to the area as a whole. How that sequence maps onto individual furnaces, slag pits and smelting sites at Lejja has not been fully documented. Even the form of the furnace has been interpreted differently: Anozie (1979) described a pit or bowl furnace at Lejja, whereas Okafor's later work indicated that what had been taken for a bowl furnace was a pit furnace into which slag was tapped (as summarised in Daraojimba et al., 2022). Detailed information on furnace structure, the operation of tuyères, the handling of slag and the extraction of blooms therefore remains limited for the Lejja sites themselves.

The third problem is spatial and social. Eze-Uzomaka et al. (2024) point out that no systematic survey had previously been linked to iron working in order to locate and explore the settlement sites associated with it, and consequently that very little is known about these early metal-producing communities or their economy. Their own survey suggests that smelting and habitation sites occupy distinct areas of the landscape, but it remains unclear whether this reflects one community with different activity areas, two communities with separate identities, or a more complex pattern in time and space. How iron production was organised, who controlled it, and how it related to farming, ritual and political authority are questions that only a combination of survey, excavation and ethnography can address.

The fourth problem is one of preservation. Slag concentrations at Lejja are exposed by erosion and road cuttings, and some blocks have been reused for erosion control in and around the Otobo Dunuoka site (Eze-Uzomaka et al., 2024). Farming, settlement expansion and road construction place further pressure on a landscape whose surface evidence is easily disturbed. At the same time, iron smelting is extinct in Lejja (Eze-Uzomaka, 2013), so that knowledge of the industry survives mainly in material remains, taboos, ritual practice and oral tradition. The fabric of the site and the memory attached to it are both at risk, and the Enugu State Government has itself acknowledged the need for measures to protect the site (Daily Trust, 2018).

This study responds to these problems by returning to the iron-smelting sites of Lejja with an explicitly archaeological question: what do the physical remains of smelting at Lejja reveal about the technology, chronology, organisation and setting of early iron production in this part of Nigeria?

1.3 AIM AND OBJECTIVES OF THE STUDY

The aim of this study is to investigate, from an archaeological perspective, the early iron smelting activities of Lejja community in Nsukka Local Government Area, Enugu State, and to establish their place in the early iron-working tradition of Nigeria. To achieve this aim, the study pursues the following specific objectives:

(i) to locate, record and map the iron-smelting sites and associated features in Lejja;

(ii) to describe the material evidence of smelting, including furnace remains, slag (cylindrical blocks and aggregate slag), tuyères, iron ore and charcoal;

(iii) to reconstruct the smelting technology employed at the sites, with particular attention to furnace type, draught and slag-handling methods;

(iv) to establish or refine the chronology of early iron smelting at Lejja by evaluating the existing radiocarbon record against new stratigraphic and technological evidence;

(v) to examine the social and ritual dimensions of the industry through oral tradition, ethnography and the spatial relationship between smelting, domestic and ancestral sites.

1.4 RESEARCH QUESTIONS

In line with the objectives, the study seeks answers to the following questions:

(i) Where are the iron-smelting sites in Lejja located, and how are they distributed in relation to domestic and ancestral sites?

(ii) What kinds of smelting remains (furnaces, slag, tuyères, ore and charcoal) are present, and how do they differ between sites?

(iii) What smelting technology was used at Lejja, and how does it relate to the early, middle and late phases defined for the Nsukka area?

(iv) When did iron smelting begin at Lejja, and how do the available radiocarbon dates compare with one another and with those from other Nsukka and Nigerian sites?

(v) What do oral tradition, taboos and the placement of slag blocks reveal about the social, political and ritual significance of iron smelting in Lejja?

1.5 SIGNIFICANCE OF THE STUDY

The study is significant in several respects.

Contribution to the debate on African metallurgy. The question of whether iron smelting in Africa was introduced from elsewhere or independently invented remains alive (Holl, 2009; Killick, 2015; Chirikure, 2015). Because Lejja has yielded some of the oldest radiocarbon determinations reported for iron smelting in Nigeria, any clarification of its chronology bears directly on that debate. By evaluating the existing dates against the stratigraphy, furnace remains and slag, the study helps to separate what is firmly established from what is still contested.

Filling a gap in the archaeology of Nsukka and Igboland. Eze-Uzomaka et al. (2024) have drawn attention to the limited and largely unpublished character of earlier survey work at Lejja. By documenting sites and features systematically and by publishing the results, the study adds to the regional database for northern Igboland, which can be compared with other Nsukka sites such as Opi, Orba, Umundu and Ukehe (Daniel et al., 2022; Daraojimba et al., 2022).

Understanding technology in its social setting. Iron production at Lejja was bound up with politics, ritual and gender, as the use of slag blocks in the village square, the taboos protecting them and the role of Dunuoka in the selection of the Eze show (Agu & Opata, 2012; Opata & Apeh, 2016; Eze-Uzomaka et al., 2024). By combining material evidence with oral tradition, the study contributes to a more complete account of how an industrial technology was embedded in community life.

Methodological value. The study brings together field survey, excavation, ethnography and the analysis of metallurgical residues, and it can draw on earlier applications of geophysical prospection at Lejja (Ogah, 2013) and at other Nigerian smelting sites (Oni et al., 2022). The resulting record can serve as a baseline for future work using archaeological science.

Heritage management and community benefit. Lejja has attracted official attention as a heritage resource in Enugu State (Daily Trust, 2018). A well-documented and dated record of the sites provides the evidence base needed for conservation planning, site interpretation, heritage education and responsible archaeotourism, and it can strengthen the community's pride in, and stewardship of, its inheritance.

Academic and training value. Finally, the study provides a worked example of archaeological investigation of an iron-smelting landscape in a Nigerian context, which can be used for teaching and for further postgraduate research in the Department of Archaeology.

1.6 SCOPE AND DELIMITATION OF THE STUDY

Geographical scope. The study is limited to Lejja community in Nsukka Local Government Area, Enugu State. Within Lejja, attention is focused on the villages known to contain iron-smelting remains, including Dunuoka (Otobo Dunuoka village square), Amaovoko and Obukpa, together with the surrounding landscape that supplied ore and fuel. Comparative reference is made to other Nsukka smelting sites and to other Nigerian sites, but these were not investigated afresh.

Temporal scope. The study concerns the Iron Age of the Lejja area, with emphasis on the early phase of smelting. Later developments, including the middle and late phases of the Nsukka sequence, are considered only to the extent that they help to define the early phase and to situate it in the longer history of the industry.

Thematic scope. The study concerns iron smelting, that is, the extraction of iron from its ore, rather than the later forging of iron objects (smithing), although smithing debris is noted where it occurs. Pottery, farming and settlement are considered as contextual evidence, not as principal subjects.

Methodological scope. The study combines archaeological reconnaissance survey, excavation, ethnographic enquiry among knowledgeable members of the community, and analysis of the recovered residues. It does not attempt a full archaeometallurgical characterisation of every sample, and the availability of radiocarbon dating is limited by cost and by the need to submit samples to external laboratories.

1.7 OPERATIONAL DEFINITION OF TERMS

For clarity, the following terms are used in this study with the meanings given below.

Archaeological investigation: the systematic process of locating, recording, excavating, analysing and interpreting the material remains of past human activity, from the discovery of a site to the publication of the findings.

Iron smelting: the process of extracting iron from iron ore by heating the ore with charcoal in a furnace so that the iron oxide is chemically reduced to metallic iron (Chirikure, 2015). In the bloomery process practised in Africa, the iron is produced as a solid, spongy mass rather than as liquid metal.

Bloom: the spongy mass of iron and slag produced in a bloomery furnace, which has to be extracted from the furnace and then consolidated by forging.

Slag: the waste product of smelting, formed from the gangue of the ore, the clay of the furnace lining and the fuel ash. In this study, tap slag refers to slag that was drained from the furnace through an opening or tuyère while smelting was in progress, cylindrical slag blocks to the solidified slag that formed when tapped slag collected in a clay-lined pit, and aggregate slag to the irregular fragments or amorphous masses produced in the later phases of the Nsukka sequence (Okafor, 1993, as summarised in Eze-Uzomaka et al., 2024).

Tuyère: the clay pipe through which air was blown into the furnace and, in some Nsukka furnaces, through which molten slag was drained (Okafor, 1993, as summarised in Eze-Uzomaka et al., 2024).

Forced-draught furnace and natural (self-induced) draught furnace: a forced-draught furnace is one in which air is blown in with bellows, whereas a natural or self-induced draught furnace draws air in through the furnace's own design without the use of bellowers (Eze-Uzomaka et al., 2024).

Early phase of iron smelting (Nsukka sequence): the earliest of the three phases of smelting defined by Okafor (1993) for the Nsukka area and dated to 2305 ± 90 to 2000 ± 90 BP, characterised by forced-draught shaft furnaces and cylindrical slag blocks.

Radiocarbon dating, BP and calibration: radiocarbon dating measures the decay of carbon-14 in organic material such as charcoal. Ages are reported as years before present (BP, with 1950 taken as the present) and must be calibrated to obtain calendar ages. Unless otherwise stated, dates quoted from earlier studies in this chapter are uncalibrated.

Ethnoarchaeology: the study of living communities, their technologies, oral traditions and beliefs, in order to help interpret archaeological remains.

Archaeometallurgy: the scientific study of the remains of metal production and working, including ores, slags, furnace fragments and metal objects.

Lejja: the community of 33 villages in Nsukka Local Government Area, Enugu State, Nigeria, which is the focus of this study (Eze-Uzomaka et al., 2024).

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