This thesis examines the social landscape of Northwest Transylvania in the Late Iron Age, Roman and post-Roman periods. This region consists of the modern Romanian counties of Cluj and Sălaj and roughly encompasses the Roman province of Dacia Porolissensis and part of Free Dacia. Roman Dacia represents an extraordinary case of Roman imperial occupation: it was one of the last major territories to be conquered and one of the first to be released. Special emphasis is placed on how Roman occupation as a phenomenon transformed the landscape; but unlike previous research the military is neither the primary focus of analysis nor the only agent of change. In the years after the Trajanic conquest of Dacia in AD 106, immigrants swarmed into the new province from all over the Empire to colonise the land which written sources indicate was severely depopulated. It was this migration as a whole that led to the destabilisation of existing Iron Age territorial units and radical transformations of settlement patterns, burial, ritual and land-use. To analyse these issues, archaeological sites and find spots of material dating to between the first century BC and the fifth century AD within the study area were entered into a database along with spatial coordinates. These data were then integrated into a Geographic Information System to facilitate geospatial analyses. These analyses indicated stark discontinuity between the Late Iron Age and Roman period in all forms of settlement and strong regional variation in every period. From the annihilation of the native communities, new ones with distinct identities emerged which found resonance after the departure of the Romans in the late third century.