This article investigates the contact-induced reorganization of the possessive system in the Gallo-Romance dialects spoken from around the 12th century in the villages of Celle and Faeto in North Apulia and Guardia Piemontese in North-West Calabria. Gallo-Romance possessives exclude the article in the prenominal position, whereas in the Southern Italian dialects, possessives follow the noun preceded by the definite article. This original contrast is no longer visible in the varieties of Celle, Faeto and Guardia which changed the original prenominal position to the postnominal position combining with the article, except with kinship terms, preserving the original prenominal position. At the heart of contact phenomena, there are bilingualism and transfer mechanisms between the languages included in the complex knowledge of the speaker, suggesting a test bed for the treatment of language variation and parameterization. We propose an account of morpho-syntactic and interpretive properties of possessives, making use of the insights from the comparison of contact systems with prenominal (Franco-Provençal and Occitan varieties) and postnominal (Southern Italian dialects) possessives. The final part examines the distribution of possessives, tracing it back to the definiteness properties of DP and proposes a phasal treatment based on syntactic and interpretive constraints.