Study suggests 2,800-year-old Ethiopian palace could have been a skyscraper-scale building

MixedA new engineering study of the Grat Be'al Gibri palace at Yeha in the Ethiopian-Eritrean highlands, dated to around 800 BC, suggests the building's walls could have supported a structure of skyscraper proportions. 1 2 MixedThe study was a collaboration led by the German Archaeological Institute (DAI) and Brandenburg University of Technology Cottbus-Senftenberg (BTU); its lead researcher is Martin Drieschner, chair of structural analysis and dynamics at BTU. 2 1 MixedThe palace was a monumental palatial and administrative complex of about 60m by 60m, the largest known palace-like structure of its period in South Arabia and East Africa. Only parts of its ground floor and foundation podium survive, and it was destroyed by fire in antiquity. 1 2

LeftIt was built of local phonolite rubble stone and clay mortar reinforced with horizontal wooden beams. Metro reports that, unlike comparable South Arabian construction, the timber was laid only horizontally; ground-floor walls were about 1.9m thick, the podium about 6m high with walls around 2.2m thick, and entrance pillars about 10m tall. 1 MixedResearchers built a virtual 3D model of two wall sections, an external corner and an internal wall with a doorway, and analysed their load-bearing capacity with the finite element method, allowing for uncertainty in the properties of the stone, clay and timber. 1 2 LeftMetro reports that earlier reconstructions envisaged five regular floors topped by three recessed storeys, and that the study found this eight-storey version well within the walls' capacity. The researchers wrote that in the worst case the building 'could have been 16 stories tall', which they called a conservative assumption. Metro adds that this is theoretical and does not mean the palace had 16 floors, and says it would have been taller than Chicago's Home Insurance Building of 1885, commonly considered the first skyscraper. 1

CentreNewsweek, quoting a BTU statement, gives a different figure: the wall system could have safely supported at least 19 floors, so the palace 'could well have reached skyscraper proportions'. 2 CentreTwo outside experts quoted by Newsweek cautioned against the modern term. Kwasi Konadu, a historian formerly at Colgate University, said a wall carrying 19 floors 'is not the same as a structure that stood 19 floors high'. Davide Tanasi, an archaeologist at the University of South Florida, said the 19 refers to a structural load factor, not a building height. 2 LeftThe study found that variation in the timber's properties had little effect on overall capacity, while the stone-and-clay masonry mattered more, with tensile failure in the clay-mortared rubble the critical limit. Metro notes that African olive and Cordia africana, both termite-resistant, have been identified among the beams, and that the researchers say an exceptional event, consistent with the fire, would have been needed to bring the building down. 1

CentreNewsweek adds that Arab historians' sources mention structures of up to 20 floors and South Arabian carvings and wall paintings depict multi-storey buildings, but no engineering analysis had backed these accounts. Tanasi called the findings 'very significant' as a quantitative assessment of a construction system archaeologists already considered sophisticated. 2 CentreBoth experts said the work challenges assumptions about ancient construction. Konadu said it undercuts the narrative of Arabia as the source of such systems in the northern Horn of Africa, and Tanasi said it shows sophisticated Ethio-Sabaean traditions beyond the usual focus on Egypt, Mesopotamia, Greece and Rome. 2