Above A possible cathedral in Adulis, Eritrea. Photogrammetry has been used to create a 3D model of the excavated remains of an important place of worship. Various different architectural and decorative influences can be detected in the structure, emphasising that this port city lies at a key maritime crossroads.

A crossroads between the seas: the origins of early Christianity

Excavations in Eritrea are revealing early Christian sites from the Kingdom of Aksum. What can these places of worship reveal about cultural connections in the 6th century AD? Gabriele Castiglia, Philippe Pergola, Stefano Bertoldi, Marco Ciliberti, Elie Essa Kas Hanna, Božana Maletic´, and Matteo Pola share the secrets of an extraordinary ecclesiastical complex.

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‘Until the borders of Ethiopia, in the region called Barbaria’: it was with these words that Cosmas Indicopleustes, a merchant and theologian from Alexandria, in Egypt, introduced the Ethiopic area at the beginning of the 6th century AD. While much about ancient Ethiopia and Barbaria continues to offer fertile ground for scholarly debate, it is certain that this area of Africa was home to thriving cosmopolitan centres. Today, the ruins of one such centre, the ancient port city of Adulis, can be found bordered by the river Haddas in present-day Eritrea, 50km south of Massaua. Adulis lies within a flat desert landscape, speckled with basalt and schist, relics of the region’s volcanic origins. The city appears in written sources that date back to the 1st century AD, such as Pliny the Elder’s Natural History and the anonymous treatise Periplus of the Erythraean Sea. Both documents indicate that the town acted as the main maritime outlet for the vast Kingdom of Aksum, which was named after its capital city, a site situated in modern Ethiopia.

A possible cathedral in Adulis, Eritrea. Photogrammetry has been used to create a 3D model of the excavated remains of an important place of worship. Various different architectural and decorative influences can be detected in the structure, emphasising that this port city lies at a key maritime crossroads.

Rise of Aksum

The Kingdom of Aksum became one of the great powers of the ancient world and ultimately controlled much of the Horn of Africa. It developed between the 1st and 8th centuries AD, with the heyday of the kingdom spanning the 4th to 6th centuries. During that period, it was the only sub-Saharan political entity minting its own coins. Aksum’s rise to prominence was aided by its control of Adulis, which brought dominance over the Red Sea. That, in turn, presented the lucrative prize of controlling long-distance commercial routes between the Mediterranean and the Indian Ocean. Most of the trade undertaken by the Kingdom involved luxury goods, such as ivory, tortoise shells, incense, and so forth, while Aksum enjoyed direct links with what are now India, China, and Sri Lanka.

Like many great powers, Aksum evolved over time. A significant religious change occurred in the first decades of the 4th century AD, during the reign of King Ezana, when the Aksumite royal court converted to Christianity. A Syrian by the name of Frumentius was duly appointed the first bishop of the capital city. Frumentius was directly nominated by Athanasius, the Patriarch of Alexandria, thereby forging a close link between the Egyptian and Ethiopian Church that endured for centuries. Less is known about the adoption of Christianity in the port city of Adulis, where the earliest record of a bishop – by the name of Moses – dates to the mid 5th century.

below Various excavations have been mounted at Adulis over the years. This plan gives a sense of what is known about the layout of the urban area following these investigations.
Various excavations have been mounted at Adulis over the years. This plan gives a sense of what is known about the layout of the urban area following these investigations.

Recent excavations at Beta Samati, in Ethiopia, have brought to light a 4th-century church. Even so, the overall implications of the archeological data from the Aksumite empire indicate that early Christianity only began to make a major material impact in the 6th century, during the Kingdom’s golden age. Aksum’s prominence was not destined to endure, though, and it was only two or so hundred years later, probably in the early 8th century, that the Kingdom entered a terminal decline. Debate about the causes of this continues, but there were probably numerous contributing factors, including wars, climatic and economic changes, as well as the Islamic invasions in the 8th-9th centuries.

European interest in Adulis can be traced back to the first decades of the 19th century, when the British diplomat Henry Salt led the first expedition to the site in 1809-1810. A second British mission followed in 1868, when it was tacked on to a military campaign, with Colonel W W Goodfellow undertaking the first excavations within the town, and bringing to light an ‘early Christian Church’. Finds from the dig were subsequently sent to the British Museum. In 1907, both the Italian archaeologist Roberto Paribeni and the Swedish missionary Richard Sundström conducted further excavations, unearthing two churches, a secular palace, and some residential areas.

Despite these discoveries, it was there that matters rested until the second half of the 20th century. Francis Anfray spearheaded a new campaign of excavations and survey in 1962 and again in 2005, with specialist analyses of the finds undertaken by the University of Southampton. Since 2011, a new project has been investigating Adulis. This work is coordinated by Ce.R.D.O. (Centre of Research on the Eastern Desert, directed by Angelo and Alfredo Castiglioni and Serena Massa), with the Pontificio Istituto di Archeologia Cristiana (PIAC) of Rome in charge of excavating and studying two of the three known early Christian churches (directed by Philippe Pergola and Gabriele Castiglia). To achieve this goal, PIAC started excavating the so-called ‘eastern church’ in 2017, while 2018 saw work start on the ‘early Christian Church’ discovered by the British team in 1868. This latter edifice is the largest Christian place of worship currently known in Adulis (which covers about 40ha). It seems likely that this building served the city as a cathedral, and the following pages will sketch out what modern research is revealing about the structure.

left The British excavations at Adulis in 1868, showing the possible cathedral as it appeared at the time.
The British excavations at Adulis in 1868, showing the possible cathedral as it appeared at the time. Image: Munro-Hay 1989.

An episcopal complex

Our suspected cathedral lies in the central-eastern portion of Adulis. The British digging at the spot involved sinking two deep trenches, which revealed some impressive ruins. Afterwards, the remains were left open to the elements, which had an impact on preservation and also allowed a wealth of waste material to build up, mainly along the outer edge of the building. Our first step in the new archaeological campaign was to remove both this rubbish and a drain installed as part of the British work, which had the handy side effect of bringing to light the entire plan of the apparent cathedral. We opted for open-area excavation, which allowed the whole complex to be opened up and studied. All of the layers within were carefully identified and recorded, while their contents were sieved using a fine mesh to ensure maximum recovery of artefacts. The only exception to this was areas where the masonry had collapsed, as attempting to sieve sizable chunks of rubble is a far from rewarding exercise!

A general view over the remains of Adulis, which lies in a flat, desert landscape.

The structure is impressive. A massive podium supports the suspected cathedral, which appears roughly rectangular in plan and comprises a large basilica-style hall divided into three naves by two rows of pillars. A semicircular apse at the end of the central nave is flanked by two lateral rooms. One of these featured a floor made of waterproof mortar, suggesting that it hosted a baptistery. Some of the material associated with the preparation of this floor was suitable for radiocarbon dating, with the results suggesting a chronology stretching back to the 6th century. This matches the implications of finds discovered within the baptistery, which include both local pottery and bronze chains associated with lamps known as polycandela. A square structure found in the centre of the apse can be identified as the altar place, while a generously proportioned threshold presents the western entrance to the complex. A large rectangular room of uncertain purpose, immediately to the west of the façade, completes the original layout of the proposed cathedral.

Over time, elements of the complex were either refurbished or rethought. These changes included reconfiguring the presbytery – that is, the area of the sanctuary to the east of the choir – which was equipped with a new Y-shaped chancel. Meanwhile, an extra room was created in the south-west portion of the cathedral. A square base at the centre of this new space indicates something significant once stood there. Perhaps this marks the former position of an altar, or alternatively the masonry might have supported a staircase, which would in turn presuppose the existence of an upper floor.

It was in the decades after these embellishments that the cathedral experienced its first phase of abandonment. Evidence for this includes traces of collapse at various places. Such structural failure did not mark the end of the cathedral as a place of worship, though. Instead, a new phase in its use was ushered in by changes to the side aisles, where two rooms were created via the simple expedient of adding two modest partition walls. Another room – this time external – was created against the east façade. Our initial reading of the site chronology places this phase in the post-Aksum era, and specifically the 9th century AD. Afterwards, the building was eventually abandoned once more, this time definitively so, with later activity restricted to the insertion of two Islamic burials – which can be radiocarbon dated to the 15th century – in the central nave.

above The main building phases of the potential cathedral. At top left, we see the various adjustments to the original structure superimposed on a single plan. At top right, the edifice is shown as originally envisioned. Note the patch of waterproof flooring in the possible baptistery at the south-east corner of the building. In the bottom left plan, a new chancel has been added to the presbytery, and an additional room created at the south-west corner of the building. At bottom right, extra rooms have been inserted into the side aisles of the hall.
The main building phases of the potential cathedral. At top left, we see the various adjustments to the original structure superimposed on a single plan. At top right, the edifice is shown as originally envisioned. Note the patch of waterproof flooring in the possible baptistery at the south-east corner of the building. In the bottom left plan, a new chancel has been added to the presbytery, and an additional room created at the south-west corner of the building. At bottom right, extra rooms have been inserted into the side aisles of the hall.

Once excavation was complete, the complex was recorded in detail, using both GPS and photogrammetry. Employing a combination of ground and elevated photographs alongside Agisoft PhotoScan allowed precisely geolocated 3D models of the remains and a digital terrain model to be developed.

Written in stone

One of the outstanding results of the recent excavations is the exceptional quantity of fragments from marble or alabaster sculptures. Studying these finds is presenting valuable information about the decorative and liturgical schemes used in Adulis, while also allowing us to focus in on the network of trade and cultural exchange along the Red Sea coast during Late Antiquity. This is well illustrated by the impressive amount of marble that must have come from the Mediterranean. Chief among this are two varieties, known as Prokonnesian and Dokimeion, which frequently feature in Byzantine ecclesiastical architecture. Both types of stone must have come from quarries in the general vicinity of Constantinople, in what is now Turkey. Two further examples of fine stone that had travelled some distance from its point of origin are Bianco e Nero Antico marble, which was quarried in the Pyrenees, and Serpentino, from the Peloponnesian region of Greece.

left The probable baptistery. Waterproof flooring can be seen at the centre left of the upper photograph, with the remainder of the apparent cathedral beyond. A detail showing both the room and the flooring is provided below left.
The probable baptistery. Waterproof flooring can be seen at the centre left of the upper photograph, with the remainder of the apparent cathedral beyond. A detail showing both the room and the flooring is provided just above.

The care taken in selecting this stone reflects its importance within the apparent cathedral. Its impressive chancel, for example, made lavish use of white marble to divide the presbytery from the central nave. Raised on a platform, it featured panels – plutei – held in place by square or octagonal pillars, some of which were surmounted by columns. Thanks to two large fragments of these panels that were recovered during the 1868 excavations, we can reconstruct the main images that graced the screen. It is clear that the plutei could bear a cross with arms that widen towards their extremities, which was either set within a round shield or superimposed on the Greek letter chi, ornamented with sprouting fleurs-de-lis and surrounded by a wreath. This style is not in itself exceptional, as comparable decorative schemes are reasonably common in the context of 6th-century Christian liturgy, especially in the Near East. Equally, it is widespread among ecclesiastical structures in the Syro-Palestinian areas and Mediterranean Egypt. Even so, Adulis can currently stake a claim to being the furthest site from the Mediterranean basin where an arrangement of this type has been detected.

below Finds from among the debris covering the probable baptistery include: (A) bronze rings, probably part of a polycandelon; (B) iron ring; (C) bronze and iron nails; (D) handle of local pottery, with an engraved cross; and (E) glass handle.
Finds from among the debris covering the probable baptistery include: (A) bronze rings, probably part of a polycandelon; (B) iron ring; (C) bronze and iron nails; (D) handle of local pottery, with an engraved cross; and (E) glass handle.

It is intriguing to compare the implications of the rich marble decoration with that fashioned from alabaster. Countless fragments of wall cladding in the form of alabaster slabs were found, but only some of them carry decorations, most of which were fairly simple. Among the exceptions are portions bearing decorative foliage, especially vine branch motifs, alongside various types of leaves and double stems. Such schemes borrow from completely different cultural coordinates to those that inspired the decorative marble. Rather than the art on the alabaster owing its origins to the Mediterranean region, this decoration displays affinities with that found along the southern shores of the Red Sea in pre-Islamic times. In particular, strong parallels can be found among the vast repertoire of bas-reliefs associated with the contemporary Kingdom of Himyar in southern Arabia.

Architectural influences

The results of our work in Adulis make it timely to consider Christian architecture in the Kingdom of Aksum more broadly. Indeed, the churches of Adulis, together with the famous examples from the cities of Aksum and Matara, are among the most remarkable ancient Christian buildings in the entire Horn of Africa. The reason for this is the innovative combination of prestigious Aksumite architecture with selected Christian-Eastern influences. One place where we can see such a fusion is in the standard church plan, which was based on the typical basilica model, usually divided into three naves, but not always with an apse. When an apse is present, it is sandwiched between two square corner rooms, an arrangement that would often have been visible in the outer façade of the building. Creating such corner rooms seems to reflect influences from the southern Levant, where it is a staple of church architecture. Equally, the use of a bema – a platform in front of the presbytery used to recite the gospel – indicates inspiration from Syria. Meanwhile, the Y-shaped presbytery seems most likely to reflect a fusion of Jerusalemite, Egyptian, and Byzantine influences. This last also accounts for a raised central nave in a number of basilicas from the Horn of Africa, which echoes an arrangement in some churches from the Greek-Anatolian area.

above The process of recording the possible cathedral included using photogrammetry to create a 3D model of the structure.
The process of recording the possible cathedral included using photogrammetry to create a 3D model of the structure.

Another distinctive element of Adulis’ ecclesiastical buildings seemingly has origins that lay closer to home. The high-stepped podiums that emphasised the supreme position of these places of worship in the urban landscape appear to draw on local traditional architecture. Such platforms could exceed 3m in height and were made up of basalt blocks, sometimes interspersed with narrow bands of shale. The pleasing pattern this created was not the only eye-catching element of the architecture, as the podium rose in a stepped formation, with its sides widening and narrowing courtesy of extensions and recesses along its length. This curious architectural game lent the churches a most unusual look, which may well have been repeated in their upper elevations, although poor preservation rarely allows clarity one way or the other.

right Excavations revealed a range of varieties of marble were employed in the structure, including examples transported from the Pyrenees and from the vicinity of Istanbul. Surviving fragments of decorative schemes can be used to reconstruct some of the designs featured on marble panels within the building.
Excavations revealed a range of varieties of marble were employed in the structure, including examples transported from the Pyrenees and from the vicinity of Istanbul. Surviving fragments of decorative schemes can be used to reconstruct some of the designs featured on marble panels within the building.

The fascination with discontinuous lines and decreasing volumes seen in the podiums is also faithfully reflected in the style of pillars used within the buildings. Intriguingly, this architectural ingredient is common to both churches and secular structures: among them stand those from Maryam Ts’iyon in Aksum and a few examples from Samidi (which lies a couple of kilometres north of Adulis). When considering columns, it is also instructive to examine the so-called ‘eastern church’ at Adulis, which was reinvestigated as part of our project. We have already seen how the pillars in the putative cathedral served to divide the basilica into three naves, creating a canonical layout. It was once thought that the ‘eastern church’ was laid out in a similar fashion, but our excavations have revealed that the situation is quite different. Rather than defining a set of linear naves, the pillars have been positioned so that they could support a dome. Such a design is familiar from prestigious places of worship in the Mediterranean, but wholly unique in the Horn of Africa during this period. Finding such a church in Adulis emphasises how receptive this entrepôt was to the important cultural innovations flowing from the Byzantine world.

left Remains of decorative alabaster elements. The surviving motifs indicate the presence of influences from the environs of the Red Sea.
Remains of decorative alabaster elements. The surviving motifs indicate the presence of influences from the environs of the Red Sea.

Our work in the ‘eastern church’ is notable, too, for uncovering a well-preserved baptismal font. This lay in a square room to the south of the church apse, placing it in the same location as the waterproof flooring suggesting a baptistery in the suspected cathedral. This overlap fits well with suggestions from other churches within the former Kingdom of Aksum that a baptistry could be found at this point.

Adulis and the Horn of Africa

The excavations in Adulis are shedding new light on Aksumite worship, which is closely connected with the Coptic Alexandrian Church. At the very beginning of Christianity in Aksum – that is, in the 4th century – worship was probably conducted in Greek, before being replaced as the liturgical language by ge‘ez, which is sometimes described as Classical Ethiopic. The Syrian origin of the first bishop of Aksum, Frumentius, helps explain why we can find many Syriac words in the liturgical ge‘ez.

below An intriguing feature is the presence of distinctive podiums, which rise in a stepped formation and abruptly change width. These examples are from Adulis (left) and Aksum (right), and seemingly reflect local architectural traditions.
An intriguing feature is the presence of distinctive podiums, which rise in a stepped formation and abruptly change width. These examples are from Adulis (left) and Aksum (right), and seemingly reflect local architectural traditions.

The Ethiopian-Eritrean Church has crafted liturgical documents of major significance to all Churches of the Christian world. Around the 5th century, the Testamentum Domini, which is one of the most important ancient liturgical sources, was translated into ge‘ez. Today, this source forms the main part of the Divine Office. The rites of Christian initiation and of penance were also enriched with elements of Latin and Armenian traditions, thanks to Ethiopian monastic communities in Jerusalem, whose liturgical cultural role was no less significant than those established in upper Egypt.

above A plan (scale in metres) and 3D digital rendering of the ‘eastern church’ at Adulis. Note how the bases for the columns in the large central room were placedso that they could support a dome.
A plan (scale in metres) and 3D digital rendering of the ‘eastern church’ at Adulis. Note how the bases for the columns in the large central room were placedso that they could support a dome.
Eritrean archaeologists excavating the potential cathedral.

Following our discoveries, there can be little doubt that Adulis is a crucial site for both understanding the world of Late Antiquity and viewing it from a wider perspective. After all, the results of our excavations show how a palimpsest of commercial, religious, and political influences could be mixed together in a melting pot that drew from an astonishing range of different cultures. What is more, studying and digging this site is not only about making scientific discoveries, it is also a way of laying foundations for the future. Every day, we work side-by-side with young Eritrean archaeologists and locals from the nearby villages of Afta and Zula e Foro. Our aim is to help transfer the practical and theoretical skills that will allow them to manage their heritage and enhance knowledge of it for generations to come.

All images: courtesy of the authors, unless otherwise stated.