The Ìjùmú Yorùbá
A comprehensive historical, linguistic, sociopolitical, and religious reference study of the Ìjùmú subgroup of the Northeast Yorùbá.
The Ìjùmú are a Yorùbá subgroup located in the western part of Kogi State within Nigeria's Niger to Benue confluence basin, forming a central component of the North-East Yorùbá dialect and cultural sphere commonly designated as Ọ̀kún . Historically organised as autonomous, decentralized village communities governed by gerontocratic councils, age-grades, and ritual societies, the Ìjùmú resisted late nineteenth-century imperial expansion by the Nupe Bida Emirate through the collective military mobilisation known as the Ọ̀gìdì Grand Alliance . Their language exhibits conservative Yoruboid phonological retentions alongside distinct morphosyntactic features, while their religious life historically prioritised territorial earth and nature spirits over anthropomorphic pan-Yorùbá deities .
Territory and Settlement Distribution
The territory inhabited by the Ìjùmú lies within the dissected hill country of the western Niger to Benue confluence basin, bordered by neighboring Ọ̀kún groups such as the Bùnú, Owé, and Yàgbà, as well as peripheral populations including the Èbìrà and Ìkàrẹ́ . Administratively, the territory corresponds primarily to the Ìjùmú Local Government Area of Kogi State, with its modern administrative headquarters located at Ìyárá .
Geographically, ecologically, and socio-politically, Ìjùmú territory is subdivided into three distinct axes:
- Gbẹdẹ (North): This northern axis comprises an undulating landscape of farming towns, including Ayétòrò-Gbẹdẹ, Ayégúnlẹ̀-Gbẹdẹ, Ìyàh-Gbẹdẹ, and Òkè-Orò-Gbẹdẹ (Okoro-Gbede) . The Gbẹdẹ settlements share direct northern frontiers with historical Nupe contact zones and trade routes leading toward the Niger River.
- Ìjùmú Àrin (Central): The central belt forms the geographical and administrative nexus of the subgroup. It contains Ìyárá, the contemporary administrative headquarters of Ìjùmú Local Government Area, alongside historical hill-fortified towns such as Ọ̀gìdì and Ìkọ̀yí .
- Ìjùmú Òkè (South): Situated in the higher elevations toward the boundary with the Ondo and Ekiti borderlands, the southern axis includes Ẹkinrin-Àddè, Ìffẹ̀-Ìjùmú, Ìyàmọ̀yé, and Àyèrè . This sector features prominent granite outcrops and rock shelters that historically served as defensive redoubts and ancient occupation sites .
Settlement patterns in Ìjùmú were deeply shaped by topography. Communities developed in close proximity to massive granite inselbergs and cave shelters, which provided defensive advantages during regional conflicts and provided the focal points for local earth shrines and ancestor veneration .
Origins, Deep Settlement, and the Autochthony Debate
The historical origins of the Ìjùmú are subject to sustained scholarly discussion, defined by a clear divergence between oral historical narratives of dynastic migration and archaeological and linguistic evidence for deep regional autochthony .
Oral Traditions of Dynastic Migration
Oral accounts standardly trace the founding of Ìjùmú communities to migrations originating from Ilé-Ifẹ̀, the spiritual cradle of Yorùbá monarchical traditions . According to these communal narratives, early settlements were established by royal princes or skilled ancestral hunters who left Ilé-Ifẹ̀ during periods of dynastic expansion or civil dispersal. In the southern town of Àyèrè, for example, oral tradition identifies the ancestral figure Olúorẹrẹ as a founder-leader who directed the initial settlement of the forest and hill tracts . Similar foundation legends are maintained across Ẹkinrin-Àddè, Ìffẹ̀-Ìjùmú, and the Gbẹdẹ towns, where specific descent groups claim direct genealogical links to ancient royal dynasties in the central Yorùbá forest zone .
However, the written historical record is silent regarding precise migration chronologies, exact itineraries, or specific regnal dates for these movements . Scholars of Yorùbá historiography note that such migration narratives frequently function in oral societies as ideological charters, legitimising land occupancy, local political hierarchies, and cultural affiliation with central Yorùbá institutions rather than providing verifiable, linear historical chronologies .
The Autochthony Model
Contrasting with the dynastic migration model, archaeological and historical research spearheaded by Ade Obayemi argues that Ìjùmú populations, along with other Ọ̀kún and Confluence groups, represent an autochthonous, aboriginal population that evolved in situ in the Niger to Benue confluence basin over millennia .
Origins of the Ìjùmú People: Scholarly Positions
┌────────────────────────────────────────────────────────────────────────────┐
│ Position A: Dynastic Migration Tradition (Oral Accounts / Paul 2021) │
│ • Origin: Emigration from Ilé-Ifẹ̀ led by royal princes and hunters. │
│ • Mechanism: Outward settlement dispersion establishing frontier polities. │
│ • Function: Cultural, ritual, and genealogical alignment with Ifẹ̀. │
├────────────────────────────────────────────────────────────────────────────┤
│ Position B: Confluence Autochthony (Archaeology & Linguistics / Obayemi) │
│ • Origin: In situ evolution in the Niger–Benue Confluence basin. │
│ • Evidence: Late Stone Age occupation at Itaakpa rock shelter (Ìffẹ̀-Ìjùmú). │
│ • Mechanism: Deep antiquity of Proto-Yoruboid separation in Confluence. │
└────────────────────────────────────────────────────────────────────────────┘
Obayemi's argument rests heavily on archaeological investigations at the Itaakpa rock shelter, situated near Ìffẹ̀-Ìjùmú . Stratified excavations at Itaakpa have yielded extensive evidence of continuous Late Stone Age and early ceramic occupation, demonstrating that human populations occupied the rocky terrain of Ìjùmú thousands of years prior to the emergence of classical Yorùbá urbanization at Ilé-Ifẹ̀ . Comparative linguistic reconstructions of Proto-Yoruboid further indicate that the Niger to Benue confluence area represents the ancient geographical homeland from which early Yorùbá, Ìṣẹ̀kírí, and Ìgálà language ancestors diverged . On this reading, the Ìjùmú are not late migrant offshoots of a centralized western kingdom, but part of the core ancestral population whose cultural and linguistic continuity developed continuously within the confluence hills .
Ilesanmi Akanmidu Paul examines how these two positions interact in the modern consciousness of the Ọ̀kún Yorùbá, observing that contemporary Ìjùmú identity synthesises both deep local autochthonous belonging and active identification with the broader pan-Yorùbá ethno-cultural matrix derived from Ifẹ̀ traditions .
The Nineteenth Century: Nupe Imperialism and the Ọ̀gìdì Grand Alliance
The nineteenth century was a transformative and catastrophic epoch for Ìjùmú society, marked by sustained military aggression, demographic dislocation, and economic exploitation by the Nupe Bida Emirate .
Nupe Incursions and Economic Exploitation
Beginning in the middle decades of the nineteenth century, forces of the expanding Bida Emirate, operating under the aegis of the Sokoto Caliphate, pushed southward into the Niger to Benue confluence basin . Exploiting their superior cavalry and firearms, Nupe commanders subjected the fragmented, decentralized communities of Ìjùmú, Bùnú, Owé, and Yàgbà to relentless seasonal military campaigns .
The consequences for Ìjùmú polities were severe:
- Tribute Extraction: Ìjùmú settlements were coerced into paying exorbitant annual tributes to Bida, primarily in the form of agricultural produce, cowries, local woven textiles, and human captives .
- Depopulation and Enslavement: Raiding parties systematically captured Ìjùmú villagers, destabilizing local farming systems and dispersing entire communities into inaccessible hilltop redoubts and rock caves .
- Destruction of Shrines and Records: The physical disruption of settlements during these raids led to the widespread destruction of communal shrines, disrupting oral lineages and ritual practices .
The Ọ̀gìdì Grand Alliance (1894–1897)
Faced with near-total subjugation, the traditionally independent and fragmented polities of Ìjùmú formed a coordinated defensive coalition known as the Ọ̀gìdì Grand Alliance between 1894 and 1897 .
Nupe Military Campaigns (Bida Emirate)
│
▼
Systematic Extraction: Tribute, Slaves, Agricultural Levy
│
▼
1894: Formation of Defensive Coalition
┌─────────────────┴─────────────────┐
│ Ọ̀gìdì Grand Alliance │
│ (Ìjùmú, Bùnú, Owé, Yàgbà, Èbìrà) │
└─────────────────┬─────────────────┘
│
Fortified Hillside Resistance
at Ọ̀gìdì Inselberg
│
▼
1897: Military Intervention by the
Royal Niger Company (Fall of Bida)
The alliance established its central military base and headquarters around the massive natural fortifications of the granite inselbergs at Ọ̀gìdì . Transcending former local autonomies, Ìjùmú communities united with neighboring Ọ̀kún groups (including the Bùnú and Owé) and elements of neighboring Èbìrà populations to mount a joint military resistance . Under the protection of the steep rocky terrain, the alliance repelled repeated assaults by Nupe cavalry and infantry forces, sustaining prolonged siege warfare .
The standoff ended in 1897, when the armed forces of the British Royal Niger Company advanced into the confluence region to break the power of the Bida Emirate . The British defeat of Bida forces at Ọ̀gìdì and the subsequent capture of Bida terminated the period of Nupe hegemony . However, this military relief was directly followed by the imposition of British colonial rule over Kabba Province, bringing a new era of administrative reorganization .
Political Architecture: Decentralization, Gerontocracy, and Modern Chieftaincy
Prior to the twentieth century, Ìjùmú political organization differed sharply from the centralized, divine monarchies characteristic of western Yorùbá kingdoms like Ọ̀yọ́, Ìjẹ̀bú, or Ifẹ̀ .
The Pre-Colonial "Mini-State" System
Pre-colonial Ìjùmú operated within what historical anthropologists and Ade Obayemi classify as a "mini-state" or segmentary political system . There was no single king or centralized dynasty exercising sovereign jurisdiction over the entire Ìjùmú collective. Instead, political authority was distributed among autonomous village polities and localized lineage compounds .
Key structural components included:
- Gerontocracy and Lineage Councils: Governance was exercised by councils of elders (àgbà) and hereditary clan heads (ìwàrẹ̀fà or council chiefs) . Political power was vested in corporate seniority, where the eldest males of lineage groups directed community administration, land allocation, and judicial dispute resolution through deliberative assemblies .
- Age-Grade Associations (Ẹgbẹ́): Community members were organized into horizontal age-grades that cut across lineage divisions. These age-grades were charged with civic responsibilities, including maintaining roads, organizing communal defense, managing collective farming operations, and policing civic conduct .
- Judicial and Masquerade Societies: Specialized masquerade institutions, such as Òkúlà, Ẹpa, and ancestral Egúngún, functioned as the highest judicial and spiritual authorities . In cases of severe social deviance, witchcraft accusations, or unresolvable civil disputes, masked ritual figures intervened, carrying out sanctions that were regarded as the absolute judgments of ancestors and earth spirits .
Colonial Reorganization and the Creation of the Olújùmú Stool
The traditional decentralized structure of Ìjùmú was dramatically altered by the British colonial administration in the early twentieth century . Seeking to implement the system of Indirect Rule across the Old Kabba Province of Northern Nigeria, colonial administrators found the decentralized lineage councils inefficient for tax collection and bureaucratic control .
Evolution of Ìjùmú Political Structure
┌──────────────────────────────────────────────────────────────────────────┐
│ Pre-Colonial Era (Pre-1900) │
│ • Segmentary, decentralized mini-states. │
│ • Autonomous village polities; no paramount monarch. │
│ • Governance by councils of elders (àgbà), ìwàrẹ̀fà, and age-grades. │
│ • Judicial enforcement via masking societies (Òkúlà, Ẹpa, Egúngún). │
├──────────────────────────────────────────────────────────────────────────┤
│ Colonial Reorganization (1930s) │
│ • British Administrative Centralization (Kabba Province). │
│ • Federation of autonomous districts (Gbẹdẹ, Ìjùmú Àrin, Ìjùmú Òkè). │
│ • Institutional invention of the paramount stool: Olújùmú of Ìjùmú. │
│ • Establishment of Ìyárá as the central administrative seat. │
└──────────────────────────────────────────────────────────────────────────┘
Through administrative reforms in the 1930s, the colonial state facilitated the federation of the autonomous Gbẹdẹ, Ìjùmú Central, and Ìjùmú South polities into a unified Ìjùmú Native Authority . As part of this consolidation, the British established the paramount royal title of the Olújùmú of Ìjùmú as a centralized chieftaincy institution, with the seat of the paramountcy established at Ìyárá . The Olújùmú stool represents a twentieth-century institutional innovation created to satisfy the demands of modern colonial and post-colonial governance, rather than an unbroken pre-colonial dynastic lineage .
Linguistic Profile: The Ìjùmú Dialect in North-East Yorùbá
Linguistically, Ìjùmú is classified under the North-East Yorùbá (NEY) dialect cluster, forming part of the Ọ̀kún language continuum spoken in Kogi, western Kwara, and peripheral borderlands . The dialect displays phonological and lexical features that distinguish it sharply from Standard (Western) Yorùbá and Central Yorùbá varieties such as Èkìtì and Ìjẹ̀ṣà .
Phonological Features
Yoruboid Dialect Phonological Comparison
┌──────────────────────┬────────────────────┬────────────────────┐
│ Feature │ Standard Yorùbá │ Ìjùmú (NEY) │
├──────────────────────┼────────────────────┼────────────────────┤
│ Oral Vowel Inventory │ 7 vowels │ 7 vowels │
│ │ (/i, e, ɛ, a, ɔ, │ (/i, e, ɛ, a, ɔ, │
│ │ o, u/) │ o, u/) │
├──────────────────────┼────────────────────┼────────────────────┤
│ Nasal Vowels │ 4 nasal vowels │ 3 nasal vowels │
│ │ (/ĩ, ɛ̃, ɔ̃, ũ/) │ (/ĩ, ã, ɔ̃/ or │
│ │ │ /ĩ, ã, ũ/) │
├──────────────────────┼────────────────────┼────────────────────┤
│ High-Back Vowel /u-/ │ Replaced by /i-/ │ Retained in word- │
│ in Noun Prefixes │ (e.g., standard │ initial position │
│ │ ìbọn, ìlú) │ (e.g., ùbọn, ùlú) │
├──────────────────────┼────────────────────┼────────────────────┤
│ Consonant Inventory │ 18 consonants │ 20–22 consonants │
├──────────────────────┼────────────────────┼────────────────────┤
│ Verbal Negation │ kò │ kè │
└──────────────────────┴────────────────────┴────────────────────┘
-
Vowel Inventory and Harmony:
- Seven Oral Vowels: Unlike Central Yorùbá dialects (such as Èkìtì and Ìjẹ̀ṣà) which employ a nine-vowel system (/i, ɪ, e, ɛ, a, ɔ, o, ʊ, u/), Ìjùmú operates with a symmetrical seven-vowel oral system (/i, e, ɛ, a, ɔ, o, u/) .
- Nasal Vowel Reduction: Ìjùmú features a reduced inventory of three phonemic nasal vowels (standardly transcribed as /ĩ, ã, ɔ̃/ or /ĩ, ã, ũ/), contrasting with the broader four-vowel nasal systems of southern and central Yorùbá .
- Word-Initial /u-/ Retention: Ìjùmú systematically retains the archaic Yoruboid word-initial high-back vowel /u-/ in nominal prefixes where Standard Yorùbá has shifted uniformly to /i-/ . For example, words for town or settlement (ùlú) and gun (ùbọn) preserve the initial /u-/.
-
Consonant Inventory:
- The dialect retains a larger consonant inventory than Standard Yorùbá, possessing between 20 and 22 consonant phonemes compared to the 18 segments of the standard language . This expansion is characterized by the distinct distribution and retention of specific plosive, affricate, and fricative phonemes across peripheral speech varieties .
Morphosyntactic and Lexical Markers
- Negative Marker: Ìjùmú utilizes the negative particle kè in verbal constructions to express negation, contrasting directly with the Standard Yorùbá negative particle kò .
- Archaic Yoruboid Lexicon: The dialect preserves an archaic vocabulary that is shared across the Ọ̀kún sphere, Olùkùmi, and adjacent Ìgálà boundaries, but absent from Standard Yorùbá . A primary lexical diagnostic is the use of the term olúku to denote "friend," contrasting with Standard Yorùbá ọ̀rẹ́ .
Scholarly Debates on Vowel Reconstruction
A major theoretical debate in Yorùbá historical linguistics centers on the origin of the seven-vowel system found in Ìjùmú and other NEY varieties .
- The Seven-Vowel Ancestral Model: Ọlásopé Oyèláràn argued that the Proto-Yorùbá ancestral language originally possessed a seven-vowel system, proposing that the nine-vowel systems of Èkìtì and Ìjẹ̀ṣà represent secondary innovations driven by vowel splitting .
- The Nine-Vowel Merger Model: Conversely, Fẹ́mi Akinkugbe and Hounkpati B. C. Capo argued that Proto-Yoruboid originally possessed an ancestral nine-vowel system with full Advanced Tongue Root (ATR) vowel harmony . In their reconstruction, the seven-vowel inventory of Ìjùmú is a derived state resulting from the merger of high-lax vowels (/ɪ, ʊ/) into high-tense or mid vowels (/i, u, e, o/) .
Linguistic Gaps in the Record
While broader Ọ̀kún linguistic surveys have documented baseline phonological profiles, the published scholarly record lacks comprehensive, isolated descriptive grammars that fully analyze tonal autosegmental processes, discourse markers, and micro-dialectal variations separating the Gbẹdẹ, Ìyárá, and Southern Ìjùmú speech communities .
Cosmology, Religious Practice, and Masquerade Systems
Traditional religious practice in Ìjùmú diverged significantly from the standard pantheon of anthropomorphic deities (òrìṣà) celebrated across the central and western Yorùbá regions .
Veneration of Ẹbọra and Imọlẹ
In mainstream central Yorùbá cosmology, devotion focused on major pan-Yorùbá anthropomorphic deities such as Ṣàngó (the thunder divinity), Ọ̀ṣun (the river goddess), and Ọbàtálá (the arch-divinity) . In traditional Ìjùmú religion, these centralized òrìṣà played a peripheral role .
Instead, indigenous religious life was dominated by the veneration of Ẹbọra (or Imọlẹ), localized territorial nature and earth spirits believed to inhabit the sacred landscape: rocks, mountain peaks, massive granite inselbergs, caves, deep pools, and pristine forest groves .
Ìjùmú Traditional Cosmology
│
▼
Ọlọ́run / High Divinity
│
┌───────────────────────────┴───────────────────────────┐
│ │
▼ ▼
Territorial Earth Spirits (Ẹbọra / Imọlẹ) Ancestral Lineages (Egúngún)
• Inhabit rocks, hills, waters, and caves • Moral and legal guardians
• Examples: Ọ̀gìdì Hill and Itaakpa spirits • Manifest in seasonal festivals
• Propitiated for community protection • Enforce social order and justice
These ẹbọra were not regarded as universal anthropomorphic gods requiring elaborate mythologies, but as localized spiritual powers possessing immediate territorial jurisdiction over specific communities . Priestly elders conducted seasonal propitiations at the base of sacred hills to ensure community protection, adequate rainfall, fertility, and agricultural bounty .
Masquerade Institutions
Masquerade institutions were central to Ìjùmú judicial administration, social cohesion, and mortuary practice . These masquerades were performed in seasonal cycles, appearing sequentially across towns like Ìyàh-Gbẹdẹ, Ọ̀gìdì, and Àyèrè between April and June :
- Ẹpa Masquerades: Carved helmet masks surmounted by towering figurative superstructures representing warriors, ancestral mothers, and hunters. Ẹpa masquerade festivals celebrated physical prowess, community cleansing, and fertility, acting as ritual conduits for revitalizing communal life .
- Uro Masquerades: Highly restricted, sacred masked figures that appeared during critical civic transitions and seasonal cleansing rites .
- Egúngún Oníyẹ (The Feather Masquerade): An ancestral masquerade adorned with elaborate plumage and indigenous textiles, embodying the physical presence of lineage ancestors returning to bless their descendants, execute moral judgments, and purify settlements .
- Òkúlà Society: An esoteric masking fraternity that maintained judicial order, investigated crimes, enforced moral codes, and conducted elite funerary procedures .
Religious Transitions and Syncretism
The intense military incursions of the Nupe Bida Emirate in the late nineteenth century disrupted traditional shrine worship and led to the destruction of oral liturgical archives . In the early twentieth century, the cessation of warfare and the introduction of Western education facilitated rapid mass conversion to Christianity (predominantly through the Sudan Interior Mission and the Anglican Church Missionary Society) and Islam .
Despite this formal theological transition, belief in the moral agency of territorial spirits and ancestral sanctions remains an active cultural force in Ìjùmú, frequently operating syncretically alongside formal Christian and Islamic practices .
Agricultural Rites and Material Culture
Agricultural cycles and distinct textile traditions define the public ceremonial life and material heritage of the Ìjùmú people .
New Yam Festivals and Ọ̀gìdì Day
The cultivation of white yams (Dioscorea rotundata) forms the economic and ritual core of traditional Ìjùmú agriculture . The agricultural calendar is structured around the annual New Yam Festival, celebrated across settlements such as Ìffẹ̀-Ìjùmú, Ẹkinrin-Àddè, and Ọ̀gìdì .
Historically, strict ritual prohibitions forbade citizens from consuming new yams prior to formal harvest rites . The local paramount ruler and chief priests were required to offer first-fruit sacrifices to ancestral lineage spirits and local ẹbọra to thank the earth and sanctify the harvest before public consumption was permitted .
In contemporary times, these harvest rites have evolved into prominent civic and cultural festivals, the most prominent being Ọ̀gìdì Day, held annually in June . Ọ̀gìdì Day serves as a socio-cultural gathering for the diaspora, featuring traditional athletic displays, the appearance of the sacred Àgbò Olóde masquerade, and the performance of distinctive polyrhythmic music played on the Ògìdìgbó, an ancient wooden slit-drum .
The Red Cloth Tradition: Aṣọ-Ìpò (or Ùpò)
One of the most distinctive material culture elements of the Ìjùmú, Bùnú, and neighboring Ọ̀kún communities is the production and ritual employment of Aṣọ-Ìpò (also termed Ùpò), a thick, handwoven red textile .
Material Culture Contrast: Funerary and Ritual Textiles
┌────────────────────────────────────────────────────────────────────────────┐
│ Western / Central Yorùbá Tradition │
│ • Dominant Funeral Cloth: White woven textiles (Alaari/Aṣọ-Ẹkú). │
│ • Red Color Value: Historically proscribed or avoided in elite burials. │
├────────────────────────────────────────────────────────────────────────────┤
│ Ìjùmú / Ọ̀kún Yorùbá Tradition (Akinwunmi 2003) │
│ • Dominant Funeral Cloth: Aṣọ-Ìpò / Ùpò (heavy handwoven red textile). │
│ • Red Color Value: Mandatory burial shroud for titled elites and elders. │
│ • Ritual Function: Masking regalia, symbol of senior ancestral transition. │
│ • Cultural Intercourse: Shared with Confluence neighbors (Èbìrà, Ìgálà). │
└────────────────────────────────────────────────────────────────────────────┘
In contrast to central and western Yorùbá cultural norms, where red fabrics were historically proscribed or avoided in mortuary contexts in favor of white cloths, Ìjùmú custom mandates the use of Aṣọ-Ìpò for the burial shrouds of senior titled elders, priests, and warrior chiefs . Aṣọ-Ìpò is woven on vertical broad looms using locally dyed red cotton threads, frequently accented with subtle structural striping . Beyond its funerary role, the cloth is an essential component of masquerade costumes and a prestige emblem worn by high-ranking lineage leaders .
Scholars trace this distinctive red cloth complex to centuries of intense commercial, artistic, and cultural interactions across the Niger to Benue confluence, linking the Ìjùmú to their Èbìrà, Ìgálà, and Bùnú neighbors .
Contemporary Situation and Regional Identity
In the contemporary Nigerian republic, the Ìjùmú constitute a politically active and educationally advanced subgroup within Kogi State . Following the administrative fragmentation of the old Northern Region and Kabba Province into successive state structures (West Central State, Kwara State, and finally Kogi State in 1991), Ìjùmú administrative interests have centered on the Ìjùmú Local Government Area .
A central issue in modern Ìjùmú political discourse is their socio-political position as a Yorùbá minority within the multi-ethnic framework of Kogi State, which includes large Èbìrà and Ìgálà populations . Ìjùmú community associations, such as the Ìjùmú Development Movement, collaborate with broader Ọ̀kún civic organizations to advocate for regional infrastructure, cultural preservation, and equitable political representation, maintaining a modern identity that bridges their ancient Confluence heritage and their broader Yorùbá linguistic kinship .
Àwọn orísun
- [1]Ade Obayemi, "States and Peoples of the Niger-Benue Confluence Area," in Obaro Ikime (ed.), Groundwork of Nigerian History (Ibadan: Heinemann Educational Books, 1980), pp. 144–164.
- [2]Hounkpati B. C. Capo, "On the high non-expanded vowels in Yoruboid," Studies in African Linguistics, Vol. 16, No. 1 (1985), pp. 103–121.
- [3]Zacchaeus Oladele Apata, "The Nupe Imperialism and the Ogidi Grand Alliance 1998–1897," in Adeagbo Akinjogbin (ed.), War and Peace in Yorubaland 1793–1893 (Ibadan: Heinemann Educational Books, 2003), pp. 241–256.
- [4]Zacchaeus Oladele Apata, Administrative Changes and Reorganisation in the Old Kabba Province of Northern Nigeria, 1897–1939 (Ph.D. Dissertation, University of Ife, 1987), pp. 88–142.
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- [8]Ilesanmi Akanmidu Paul, "The Migration Patterns and Identity of the Okun-Yoruba People of Central Nigeria," Yoruba Studies Review, Vol. 6, No. 1 (2016), pp. 115–134.
- [9]Olugbenga Oladeji Abokede and Stephen Ayodele Ayinmode, "Classification of Ẹpa Masquerades among Okun Yoruba of South Western Nigeria: A Study of Forms and Aesthetics," American International Journal of Research in Humanities, Arts and Social Sciences, Vol. 23, No. 1 (2018), pp. 48–54.
- [10]Oluwafemi Akinkugbe, A Comparative Phonology of Yoruba Dialects, Iṣẹkiri and Igala (Ph.D. Dissertation, University of Ibadan, 1976 / 1978), pp. 112–158.
- [11]ProQuest Dissertations / Field Studies, Ritualization of Food Security Practices and Memories Among the Okun-Yoruba People: A Case Study of New Yam Festivals of Ijumu Land (Ann Arbor: ProQuest LLC, 2022), pp. 54–89.
- [12]T. Akinwunmi, "The 'Aso-Ipo' Red Cloth of the Bunu and Okun-Yoruba," in Ayodeji Olukoju, Z. O. Apata, and O. Akinwumi (eds.), Northeast Yorubaland: Studies in the History and Culture of a Frontier Area (Ibadan: Rex Charles Publication, 2003), pp. 165–182.