From organizing center to threshold configuration: a morphogenetic reading of Aleppo’s long-term urban transformation

Abstract

Purpose This article examines Aleppo as a long-term urban transformation process and asks how organizing centers, mobility/access structures and socio-spatial differentiation shaped its urban form across successive historical phases. Here, morphogenesis is understood as the historical-spatial process through which urban form is generated, stabilized, transformed and reworked over time. Design/methodology/approach The article uses a qualitative historical-spatial design based on documentary sources, historical cartography, secondary morphological scholarship and interpretive schematic reconstruction. Evidence is organized through a consistent analytical grid: organizing center, access/mobility structure, socio-spatial differentiation and morphological outcome. Findings Aleppo did not evolve as a homogeneous center-periphery system. Its urban structure was repeatedly reworked through the persistence of the citadel hill, the articulation of political, religious and commercial poles, the differentiation of confessional and occupational domains, the formation of threshold-like internal interfaces and later westward and proto-polycentric tendencies. Research limitations/implications The article is interpretive and historical-spatial in scope; it does not provide quantitative measurement, exhaustive archival reconstruction or direct evaluation of contemporary planning interventions. Its findings are therefore analytical rather than statistically generalizable. However, the framework offers important implications for urban morphology and planning by showing how historic cities can be studied through organizing centers, mobility/access structures, threshold configurations and evolving centralities. Future research may strengthen this approach through GIS-based reconstruction, georeferenced archival data, multi-scalar morphological mapping and comparative studies of other historically layered metropolitan cities. Practical implications The findings support heritage-sensitive planning strategies that protect the fragile historic core while strengthening secondary centralities, corridors and distributed functional organization. Social implications The article highlights that historically layered cities such as Aleppo should be planned in ways that protect living heritage while supporting more balanced urban life. By showing the risks of overconcentrating functions in a fragile historic core, it points toward a more equitable distribution of services, accessibility and urban opportunities across multiple centralities. This can help reduce pressure on vulnerable heritage areas, improve everyday mobility and support socially inclusive urban development. More broadly, the article reinforces the social value of linking heritage protection with quality of life and balanced metropolitan growth. Originality/value The article clarifies how morphogenesis can be operationalized within urban morphology by linking historical evidence to spatial mechanisms. It also integrates fragmented scholarship on Aleppo into one explanatory framework focused on centrality, access, socio-spatial occupation and form.