The Federal Civil Code of the United States of Mexico serves as the foundational legal framework governing civil relations within the nation. Its comprehensive structure addresses a myriad of aspects, from individuals and family law to property, contracts, and, crucially, inheritance. The Third Book, specifically dedicated to "Of Inheritance," lays out the intricate rules and principles that dictate how a deceased person's assets, rights, and obligations are transferred to their successors. Understanding these preliminary provisions is essential for anyone dealing with estate planning, legal succession, or the administration of a deceased person's property in Mexico. This in-depth analysis will delve into the First Title of the Third Book, focusing on the "Preliminary Provisions" that establish the core concepts and definitions of Mexican inheritance law. We will explore the distinctions between testamentary and legitimate succession, the roles of heirs a...