Conducted within the framework of a formal agreement between the French National Centre for Scientific Research (CNRS, UMR 8167 “Orient & Méditerranée”) and the Saudi authorities responsible for antiquities, the project has concentrated on the residential and administrative core of Hegra, enclosed by a mudbrick rampart approximately three kilometres in length and encompassing roughly fifty-two hectares. While Madâin Ṣāliḥ has long been known for its monumental rock-cut tombs, the MSAP has shifted scholarly attention toward the urban fabric within the walls, exposing domestic quarters, defensive systems, a Roman fort, gates, towers, and a major Nabataean sanctuary.

The project has integrated stratigraphic excavation, architectural study, numismatics, ceramic analysis, archaeozoology, epigraphy, and materials science to clarify the chronological development of the city from its Nabataean florescence in the late first century BCE and first century CE through its incorporation into the Roman province of Arabia and its late antique transformation.

Hegra, identified with ancient al-Ḥijr, constituted the southernmost principal urban center of the Nabataean Kingdom. Its strategic position along caravan routes linking southern Arabia, the Levant, and the Mediterranean made it both a commercial and administrative hub. After the Roman annexation of the Nabataean Kingdom in 106 CE under Trajan, Hegra became integrated into the provincial system of Arabia Petraea.

Although the site’s funerary architecture has been documented since the nineteenth century CE, archaeological investigation of the walled city remained limited until the early twenty-first century CE. The MSAP addressed this lacuna by undertaking controlled excavations within the enclosed settlement, thereby reconstructing urban planning, defensive modifications, religious topography, and patterns of occupation extending from at least the second century BCE into the fourth century CE. The evidence indicates a dynamic urban history marked by Nabataean expansion, Roman military presence, structural reinforcement during the third century CE, and eventual civilian reuse of former military and sacred spaces.

circa 100 CE

The Madâin Ṣāliḥ Archaeological Project was formalized under a multi-year agreement signed for the period 2014–2018 between the CNRS and the Saudi Commission for Tourism and Antiquities, under the presidency of Prince Sultan bin Salman bin ʿAbd al-ʿAziz. Directed by Laïla Nehmé, the mission brought together specialists in archaeology, architecture, epigraphy, ceramics, numismatics, archaeozoology, and conservation.

Earlier exploratory campaigns had identified key sectors within the walled city, but the 2016 and 2017 seasons marked a decisive phase of intensive stratigraphic excavation in six principal areas, including the Roman fort, the South-East Gate, two towers on the eastern rampart, a large sanctuary complex centered on the sandstone outcrop designated IGN 132, and a domestic quarter in Area 9. The project’s structure reflects a collaborative model in which excavation, specialist analysis, and publication proceed in parallel, with full reports submitted to Saudi authorities and scholarly syntheses prepared for publication in Atlal, the journal of Saudi Arabian archaeology.

circa 100 CE

Objectives and Methodology
The project’s primary objective has been to reconstruct the urban and institutional development of Hegra within its fortified perimeter. Particular emphasis has been placed on clarifying the chronology of the city wall and its gates, identifying and dating Roman military installations, defining the architectural sequence of religious complexes, and integrating epigraphic data into spatial analysis.

Methodologically, the project employs stratigraphic excavation with detailed locus recording, architectural measurement calibrated against Roman and local construction standards, and systematic artefact registration. Ceramic assemblages are analyzed typologically and chronologically to establish occupation phases, while coins provide termini post quem and relative sequencing. Radiocarbon dating has been used selectively to refine pre-Roman horizons.

Faunal remains are examined to determine species frequencies, butchery patterns, and provisioning systems, particularly in military contexts. Epigraphic documentation includes georeferenced recording, photographic analysis, and re-examination of previously published inscriptions in Dadanitic, Nabataean, Ancient North Arabian, Ancient South Arabian, Greek, and Latin scripts. The integration of these approaches permits correlation between architectural phases, material culture, and historical frameworks.

circa 100 CE

Roman Fort
Excavations in Area 34 established the existence of a Roman fort occupying a stony plateau west of a hilltop citadel. The structure is a quadrangular enclosure measuring approximately eighty-five metres east–west by over sixty-five metres north–south. Three perimeter walls survive, while the fourth side is defined by a multi-room building interpreted as eastern barracks. Measurements correspond closely to Roman modular planning in pes monetalis units, indicating formal military engineering. Ceramic and stratigraphic evidence date the fort’s construction to the early second century CE, placing it among the earliest Roman military installations in Arabia.

Surface clearance and trench excavation revealed substantial quantities of bronze military fittings, including tie-hooks, strap junctions, buckles, and elements possibly associated with horse harness or scale armor. A baldric fastener finds parallels at Dura Europos in the second to third centuries CE. Inside one room, a ritual deposit consisting of bronze figurines, including representations identified as Priapus and possibly Harpocrates, was discovered beneath an intentionally overturned basin. Mid-third century modifications include the blocking of a southern postern gate and the addition of buttresses along the curtain wall, suggesting emergency reinforcement during a period of instability. Evidence of fire in one room and subsequent reorganization indicates structural disruption, yet military occupation continued into the late third or early fourth century CE, after which parts of the fort were reoccupied by civilians. The archaeozoological assemblage, dominated by camel and other large mammals, supports interpretation of a centrally supplied garrison operating under a commissariat-like system.

circa 100 CE

South-East Gate
The South-East Gate, excavated between 2011 and 2017, preserves evidence of multiple construction phases spanning the Nabataean and Roman periods. The visible remains correspond to a Roman rebuilding in stone within a mudbrick rampart exceeding two metres in thickness at this point. The gateway, approximately 3.75 metres wide, is flanked by two rectangular towers measuring over six metres in length. Reused inscribed stones incorporated into the masonry include Greek and Latin texts. A Latin inscription referring to Marcus Aurelius Antoninus provides a terminus post quem of 170 CE for the Roman reconstruction. Greek graffiti carved in situ by soldiers, including the name Komodos, indicate active use by Roman military personnel in the late second and early third centuries CE.

A striking find outside one of the towers consisted of a decapitated human skull deposited within a refuse layer. Osteological analysis confirmed decapitation and identified a healed cranial wound, possibly from a projectile. The skull’s position suggests either deliberate disposal or the fall of a displayed head from a pike near the gate, implying a punitive or demonstrative act in a prominent public location.

circa 100 CE

Nabataean Gate
Beneath the Roman structure lay the remains of an earlier Nabataean gate constructed in the first century CE. Although heavily dismantled, its foundations and floor levels were documented in deep soundings east of the Roman towers. Stratigraphy indicates a prolonged period of abandonment between the cessation of the Nabataean gate’s use and the erection of the Roman replacement. This interval was marked by significant sand deposition, suggesting reduced maintenance or partial desertion of the defensive line prior to Roman military reorganization. The dismantling and reuse of blocks from the Nabataean gate, as well as from a nearby Roman military shrine, demonstrate continuity of building materials even amid architectural transformation.

circa 100 CE

Roman Gate
The Roman phase of the South-East Gate, constructed between the late 170s and the 190s CE, represents a formalized military entrance integrated into the fortified perimeter. Its towers, threshold, and controlled passage align with Roman defensive typologies observed elsewhere in Arabia Petraea. The reuse of inscribed blocks, some originally associated with a shrine active into the 170s CE, indicates both pragmatic recycling and the reconfiguration of religious and civic spaces under Roman authority. Subsequent minor architectural modifications reflect continued occupation and adaptation through the third century CE, possibly extending into the early fourth century before military withdrawal.

circa 100 CE

Towers on the Eastern Rampart
Excavation of Towers 22 and 16 along the eastern rampart clarified the defensive sequence of the city wall. Both towers abut a widened second phase of the rampart, which expanded from approximately 1.4–1.5 metres to nearly two metres in thickness. Tower 22 revealed an earlier occupation horizon beneath the rampart characterized by an ashy layer with associated domestic or small-scale industrial material. Radiocarbon dating of charcoal from this context yielded a calibrated range between 154 BCE and 58 CE, suggesting activity preceding or coinciding with early Nabataean urban development. Tower 16 preserved evidence of an upper terrace constructed with reeds and palm trunks and contained basins likely used for storing water during guard duty. The towers were therefore later additions to an already established defensive wall, reflecting reinforcement and perhaps increased militarization during the Roman period.

circa 100 CE

Nabataean Sanctuary
Area 6, centered on the sandstone outcrop designated IGN 132, constitutes the largest intra-muros sanctuary identified at Hegra. The outcrop rises approximately sixteen metres above the surrounding plain and is enclosed by a temenos wall defining a sacred precinct. On its summit stood a monumental tetrapylon surrounded by a sandstone enclosure, forming a conspicuous landmark within the city. Stratigraphic analysis distinguished four phases.

The earliest phase, predating the late first century BCE, includes rock-cut niches with betyls carved into the outcrop’s southern flank. The principal Nabataean phase, spanning the late first century BCE and first century CE, established the temenos wall, annex rooms, a well and cistern system, and monumental architectural elements including an Ionic doorjamb capital comparable to examples dated between 25 and 75 CE. The sanctuary likely comprised both upper and lower components linked architecturally and ritually.

During the second and early third centuries CE, the sanctuary retained monumental character, as indicated by decorated architectural blocks in Roman levels. After approximately 270 CE, craft and possibly domestic activities occupied the enclosure, utilizing its walls for shelter. No firm evidence of occupation extends beyond the early fifth century CE. An inscription discovered nearby invoking šmyʾ, “Heaven,” may point to a locally significant supreme deity, though definitive attribution of the sanctuary’s cult remains uncertain.

circa 100 CE

Systematic study of ceramics has provided the chronological backbone for all excavation areas, distinguishing phases from the second century BCE through the fourth century CE. Numismatic research has focused in part on the so-called “Owl” coins, a substantial assemblage derived from Athenian prototypes of the fifth century BCE but locally produced in varying standards between the fourth and first centuries BCE. Recent reassessment suggests these issues may be attributable to the Lihyanite Kingdom and potentially minted at Hegra, reshaping understanding of pre-Nabataean political and economic structures in the oasis.

Faunal analysis from the Roman fort demonstrates a predominance of camel remains across Nabataean, transitional, and Roman levels, with extensive butchery marks indicating systematic consumption. The distribution and modification of bones suggest centralized supply rather than household-scale slaughter. Modified astragali, including smoothed or perforated examples, correspond to broader patterns of gaming, ritual, or symbolic use documented across the Mediterranean and Near East. Together, these artefactual studies integrate economic, dietary, and cultural dimensions into the architectural narrative.

circa 100 CE

The Madâin Ṣāliḥ Archaeological Project has fundamentally altered scholarly perception of Hegra by revealing the complexity of its urban core beyond its celebrated funerary monuments. The identification of a purpose-built Roman fort confirms sustained military presence in northwestern Arabia during the second and third centuries CE and situates Hegra within the defensive infrastructure of Arabia Petraea. The excavation of the South-East Gate and rampart towers clarifies the city’s defensive evolution from Nabataean to Roman control. The sanctuary at IGN 132 demonstrates that substantial intra-muros cult architecture existed alongside the rock-cut necropoleis, reshaping interpretations of Nabataean religious topography.

By integrating stratigraphy, epigraphy, numismatics, and archaeozoology, the project provides a coherent chronological framework spanning the second century BCE to the fourth century CE. Its findings illuminate processes of political transition, military adaptation, religious continuity and transformation, and eventual late antique reuse. In doing so, MSAP establishes Hegra as one of the best-documented urban centers of northern Arabia across the Nabataean and Roman periods, contributing decisively to the archaeology of Arabia between circa 200 BCE and 400 CE.