The paper examines the evolution in the presence of banks, whose headquartes are in the Centre-Northern Italy, in the southern banking system. Analysing market shares in loans, deposits and branches emerges an increase in the incidence of banks not from the Southern area in the relationships with southern clients. This occurred mainly in the second half of the Nineties and in the first years of new millennium. After a first period characterized mainly by mergers; in the second half of the Nineties there were mainly acquisitions of control by Centre-Northern banking groups of southern banks which maintained their formal juridical independence. Also the importance for Centre-Northern banks of their relationships with southern clients increased, moreover, on the other hand, the relevance of Centre-Northern clients for southern banks is not negligible. Lastly, the paper proposes a comparison between the national integration of the southern banking system and that of the banking system of similar emergent areas in Spain and Germany. Previous results highlight that Italian southern banking system is relatively more integrated with the national one than that of Spain and Germany.