Metropolitan growth in Europe has resulted in drastic changes of urban forms, socio-spatial structures and land-use patterns due to sequential processes of urbanization, suburbanization and re-urbanization. To assess latent shifts from mono-centric models towards more disarticulated and decentralized settlement configurations, the present study evaluates spatio-temporal patterns of growth between the 1920s and the 2010s in three Mediterranean cities with different structure and functions (Barcelona: compact and moderately polycentric; Rome: dispersed, medium-density; Athens: mono-centric, hyper-compact). To identify and characterize long-term urban transformations, an original approach was illustrated in this study, based on a multivariate analysis of 13 indicators resulting from descriptive statistics and linear regression modeling the relationship between population density and distance from inner cities. The empirical results of this study indicate that Barcelona, Rome and Athens have experienced different urbanization cycles, characterized by a (more or less) concentrated distribution of population along urban gradients. Despite similarities in demographic dynamics and planning practices, these processes have determined (i) a mostly centralized growth in Barcelona, (ii) a relatively dispersed and discontinuous spatial structure in Rome, and (iii) a steep decline of population density with the distance from downtown Athens. Compact urban expansion, population decline and urban de-concentration were finally assessed using the analytical approach proposed in this study.peri-urban landscapes [13]. Metropolitan areas in Europe have undergone changes in both structure and functions reflecting sequential cycles of compact and dispersed urbanization [14][15][16].The inherent differences in urbanization patterns and processes across countries make the identification of spatio-temporal dynamics of urban change progressively more difficult when considering the effects and consequences of exurban development [17][18][19][20]. Based on the intrinsic nature of societies and economic systems, recent transformations from mono-centric to polycentric structures have attracted rising attention among the social sciences [21][22][23][24]. The identification of mono-centric and polycentric patterns of growth has benefited from a broad range of approaches derived from different disciplines [5,[25][26][27]. Being an explicit target of the European Spatial Development Perspective [28], polycentrism in Europe has influenced forms of human settlements and socio-spatial structures altering the short-and medium-term dynamics of economic activity [29][30][31][32].Until the early 1990s, large metropolitan areas in Mediterranean Europe have been frequently considered as regions with structurally compact urban forms and functionally monocentric spatial organizations [33][34][35]. Leontidou [36] highlighted similarities in the individual trajectories of urban growth, leading to convergent socio-spatial profiles and homogeneous economic struc...