Rezumat
The present article focuses on the concept of medieval common law present in the space around the Carpathian Mountains, Transylvania and the medieval Kingdom of Poland. The law of the land that was used by the local “voievod” and/or “cneaz” was called the ius valachicum. Our research attempts to identify and clarify this concept of the lex Olachorum, based on original documents and terminology versus applicability in the medieval kingdom of Hungary, and the medieval kingdom of Poland until the dissolution of the territorial-social aggregation form known as “cnezat”, from a historical and juridical approach.