Continental codes have been presented, following in the French model's footsteps, as a determining technique to achieve legal unification and legal positivism. From this perspective, codes would not be compatible with non-legal sources (custom, judicial precedent, legal doctrine) and with legal diversity. Looking at the Spanish case one comes to the conclusion that these ideas are myths or, at least, are not entirely true. They may be true for the French case or even for other European jurisdictions, but they failed when applied to Spain. This may explain why non-Spanish legal historians and comparative lawyers seem to find it difficult to understand the Codification of Civil law in Spain. On the one hand, the French influenced over the Spanish civil code is exaggerated. On the other, it would be unimaginable that the French civil code would have supposed to be applicable in defect of regional laws or customs, as it is the case in Spain. Besides, the Napoleon code did not recognize explicitly the custom as a legal source, whereas in the Spanish code did. It is undeniable that drafters of the Spanish civil code had in mind and used the French model, but the final outcome was quite unique. Spain shows that codification does not necessarily imply legal unification. In fact, Spain constitutes the only case in which the civil code whose application is just subsidiary, that is, when regional laws do not contain a legal rule applicable to solve a legal dispute. In explaining this from a historical and comparative perspective, non-Spanish scholars usually identify regional laws (Derechos forales) with fueros, customs and local laws, but this is not entirely true. The problem is that no other civil law jurisdictions can be used as a model to describe the Spanish case, which on this matter is unique. The paper focuses on the uniqueness of the Spanish case in codifying its civil law, dispelling some myths and misunderstandings on the notion of codification in general, and on the Spanish civil code in particular.