This book is a summary of the extensive research by the co-authors on the validity and application of the 1804 French Civil Code in the Free City of Cracow (1815-1846), the Polish constitutional city-state established at the Congress of Vienna. From the wealth of case-law and legal practice of the Cracovian Republic, there emerges a picture in which its inhabitants were consciously and consistently building the structure of a modern state. As far as was possible amid the realities of post-feudal society, this state was already based on the rule of law. One of the basic elements of this legal structure was precisely the Napoleonic Code, which established the framework for the private law of the Free City, and made it a very small, but important, part of European legal heritage.