Earthworks of Ijebu-Ode

Sequel to the archaeological survey carried out in Ijebu-Ode 2017, sites were identified and excavated in the 2018 field season. These sites are situated around the vicinity of earthworks. Earthworks are common in West Africa. Some researchers have argued that the functions of earthen architectural features in the form of banks, walls, and ditches vary from simple domestic usage to formal military defense of cities. Others have argued that they are defensive structures employed by elite and non-elites in their respective zones. In patterns, some earthworks appear in packed and clustered forms and are mostly boundary markers between landed property owners. Others are linear and extensive, enclosing a community. In the Yoruba-Edo region of Nigeria, these earthworks vary from small-scale enclosures surrounding modest compounds to walls around towns, and large-scale embankments enveloping urban centers. This year, I examined the Ijebu earthworks, in particular, those enclosing Ijebu-Ode, the capital of Ijebu polity. I report on the most recent survey and excavation carried out in Ijebu-Ode. I draw upon the relationship between Ijebu inner walls and the outer enclosures.Capture   Picture1

There are two main kinds of earthworks: free-standing walls and dump ramparts. Free-standing walls are built from mud and bricks by molding or stacking muds or bricks over a uniform landscape to form a vertical wall. Dump ramparts are formed by digging earth from one side to be accumulated on the other side, thereby, building a wall or a bank formed at an angle of inclination. The side which is being dug forms the ditch. Therefore, for every bank formed, there is a ditch. The bigger the bank, the wider and deeper the ditch. Some free-standing walls may also have ditches that expressed more, their militaristic function. The northern part of Nigeria which is situated in the Savannah mostly have free-standing earthworks. However, the Ijebu earthworks like most others in the rainforest have the dump ramparts.

Ijebu is a vast kingdom in the southwestern part of Nigeria. Early historical records showed that Ijebu was a center of commercial activities. Pacheco Pereira, a Portuguese chronicler in the 16th century described Ijebu-Ode as the capital of the Ijebu polity. Pereira must have visited ‘Rio de Lago’ which is the Lagos Sea, at the close of the 15th century. His writing was the first piece where Ijebu was mentioned as ‘Geebu.’ At this time, the Ijebu kingdom was accessed through the Lagos Lagoon. Pereira’s description picturizes Ijebu as a socially and politically independent kingdom that is economically prosperous. He states that “…………above this river is a great city called Geebu, surrounded by a great ditch… (Pereira 1905), highlighting the presence of earthworks in the early 16th century.


The oral and written histories on Ijebu opens the door to the possibilities of carrying out archaeological research within the proximity of Ijebu-Ode and the outlying settlements. To date, there have been up to eight archaeological inquiries on Ijebu. Seven researchers, including the present author, attempted to explore the archaeology of Ijebu earthworks. The most significant of the earthworks is Sungbo Eredo, which is approximately 180km in circumference and surrounds the whole of Ijebu kingdom. Peter Lloyd was the first to mention this earthwork in his survey report. Patrick Darling continued to hunt for earthworks in the Yoruba-Edo region, taking a cue from Benin to examine the extent of Sungbo Eredo. David Aremu  seeks to ensure that the earthwork is conserved and listed as a world heritage while Joanne Mary and the present author worked with him in excavating portions of the earthwork to reconstruct its depositional history. Olusegun Opadeji discovered iron working sites of over 500 furnaces within the proximity of Sungbo Eredo and concludes that this site might be the production site of iron objects needed to dig a part of the 180km long earthwork that is up to 10m deep at some points. A major problem in Ijebu archaeology was the contextual and chronological relationship with the Ijebu polity as the previous dating of the earthworks was inconsistent with oral traditions. It was Ife-Sungbo Archaeological Project, directed by Chouin and Ogunfolakan in collaboration with scholars from the University of Ibadan who attempted to solve the chronological and historiographic dilemma. All of these archaeological endeavors point to the Earthwork of Ijebu as a significant tool and driver employed by a large polity based on the massive size of the structures as well as the technological requirements to build it.

Although Llyod in the late 1950’s, and Patrick Darling in the late 1990’s carried out reconnaissance survey of Sungbo Eredo (the outer enclosure of the whole Kingdom), its archaeology is just beginning to take shape only within the last six years opine that the site of Sungbo Eredo at the Oke-Eri axis Northern axis is about 5000 years Bp. This date has been debated to be an outlier. It has been clarified to be incoherent with the construction of Sungbo Eredo around the late 14th or early 15th century. In 2014, working under the supervision of David Aremu, I excavated a test unit on the Oke-Eri bank. In asserting or refuting the earlier date, my unit was marked closed to the trench that yielded a date of 5000 years Bp in 2014. The dates gotten from this excavation further complicated the chronology of Sungbo Eredo as it goes back to 10000 years Bp. However, the charcoal samples dated came from an older surface that existed before the construction of the earthwork thereby establishing the possibilities of two occupations; the Late Stone Age, and the neolithic period. After this work, which contributed to the understanding of the depositional history of a part of the outer ditch, I took part in the 2016 season of the Ife-Sungbo project jointly led by Gérard Chouin (William and Mary) and Adisa Ogunfolakan (Obafemi Awolowo University, Ile-Ife). This time, the team was able to obtain a full stratigraphic profile of the ditch-and-bank enclosure at Ilara-Epe, Lagos State, and dated to the late 14th to early 15th c. This date is relatively similar to dates published by Connah on the earthworks of Benin City to coincide with periods of rising, migration, and the collapse of kingdoms in West Africa.

Having had a chronological idea of the outer earthwork, there is thus need to look into the capital of the vast kingdom. In looking at Llyod’s survey map, one could see the traces of inner ditch system within the center of Ijebu Kingdom. Although the exact location of this inner feature could not be deciphered from the map, google earth satellite  maps played a pivotal role in locating the features. I consequently carried out an intensive survey of Ijebu-Ode. It is now established that Ijebu kingdom has both outer (Sungbo Eredo) and inner enclosures. It was not difficult to propose that the polity which commanded the construction of a longer outer 180km long earthwork might have its political and commercial headquarters within the inner enclosures.

I identified two different enclosures in Ijebu-Ode. One which surrounds the palace area as shown in the 1892 archival records. It is clear that the innermost earthwork was still very much visible up to the late 19th century. The other which surrounds the interspersed land beyond the palace area earthwork, thus forming a concentric layer of enclosures.

This archive map showed the innermost enclosure as having six different gates to gaining entrance into the capital. Like, Benin and Oyo, the palace of Ijebu titular head is situated within the innermost wall, turning light into both boundary marking and the protection of the capital of Ijebu kingdom. The capital must have been the commercial, economic, political, and cosmological headquarters of the whole kingdom. It is on this note that I decided to excavate a few portions of the 100m left over vestiges within Anglican Girls Grammar School.

As AGGS, two portions were excavated; 1. a 2X3m units that have 1/3 of its length previously submerged by the bank. (2). 3 X 6m just outside the bank. AGGS 1 produced no cultural materials at the portion overlaid by the bank. Only a few materials were gotten from the remaining 2/3 part of the Unit. This is unlike AGGS 2 which produced numerous ceramics that looked like the remains of a settlement. At about 50cm deep, two features were found. These features were joined by a conglomeration by ceramic sherds. Feature 1 produced a pot that is in an inverted position. Feature 2 excavation produced potsherds of diverse forms. The decorative motifs of these ceramics are carved wooden roulettes with some chevron styles.





Ijebu-Ode was not isolated from the vast Ijebu-Kingdom encountered in the 15th century by Pacheco Pereira. Indeed, it was the center of the large polity.

Ijebu kingdom had three concentric earthworks; 1. Sungbo Eredo that marked Ijebu Kingdom 2. A Little known earthwork that might be for the middle class population within Ijebu-Ode, and the innermost one that enclosed the palace area.

The Ijebu-Ode earthworks is a proof that Ijebu-Ode was an urban center at the time the earthwork was functional. The maps showed the centrality of Ijebu Palace outstretched by gates and wickets. The configuration followed Llyod’s description of a typical Yoruba urban space. Llyod  noted that in characterizing Yoruba capitals, one should look out for “ a rampart and ditch enclosed a densely built-up area in the centre of which was the Oba’s palace—an assemblage  of courtyards with specific ritual and secular uses, facing a large, open concourse, the whole covering several acres. In front of the palace was the main market of the town, with roads radiating to the towns gates and beyond to the subordinate towns of kingdoms.” This description can be clearly seen in the retrieved Ijebu map. One advantage is that it will also help in the search for old palace and market square in future works. Searching, identifying, and excavating the palace illustrated on the map seems to be a step in the right direction to having a fuller picture of Ijebu between the late 14th century and the late 19th century.