In This Article Expand or collapse the "in this article" section Uti Possidetis Iuris

  • Introduction
  • Introductory Works
  • Textbooks
  • Specialized Works
  • Stability of Borders
  • Boundary, Line, or an Abstraction

International Law Uti Possidetis Iuris
Fozia Lone
  • LAST REVIEWED: 23 March 2012
  • LAST MODIFIED: 23 March 2012
  • DOI: 10.1093/obo/9780199796953-0065


The literature on the concept of uti possidetis shows deep links to colonization, self-determination, territorial integrity, sovereignty, statehood, creation of states, and territorial boundaries. The controversial notion of uti possidetis has shaped many modern states and created new identities for postcolonial states. In creating new identities, it dismantled precolonial identities of nations. Hence, in many instances it became a source of relentless battles and on many occasions bloody wars. A prodigious amount of literature exists on the principle of uti possidetis, including its origin, usage, and relation to issues of decolonization and self-determination. This Roman law doctrine was used to stabilize the border not only in the Spanish Empire in South America after the Spanish withdrawal but also during the decolonization process in Africa and Asia. The purpose of this principle was to maintain the territorial stability of newly created states at the time of decolonization and also to resolve issues related to title, boundary demarcation, and delimitation of maritime areas in situations in which a treaty did not exist or did not deal with such issues. The legal character of this principle is unclear; however, depending on various situations, it has been referred to as a rule, principle, customary international law, technique, policy decision, and political tenet. The principle of uti possidetis iuris favors actual possession regardless of how it was reached and does not distinguish between de facto and de jure possession. These colonial administrative borders almost never were drawn to conform to the boundaries of the inhabiting populations and almost always cut through them, resulting in nations becoming trapped within new states. This indiscriminate application of uti possidetis iuris in the name of acquiring “stability and finality” resulted in many claims of the right to self-determination and border disputes. This principle is prized by states that emerged through the decolonization process, because it guarantees their territorial integrity. Over the years the principle of uti possidetis has been stretched and applied to postcolonial borders to maintain the finality of borders in situations such as territorial breakups, an example being Yugoslavia.

Introductory Works

The term uti possidetis was first applied by Roman magistrates in private municipal law. Moore 1913 clarifies use of uti possidetis during the Roman era as a principle that preserved possession of an immovable property of individuals who had possession, even if they could not show an original title. The formula adopted by the praetor was as follows: “As you possess the house in question, the one not having obtained it by force, clandestinely, or by permission from the other, I forbid force to be used to the end that you may not continue so to possess it” (Moore 1913, p. 6). The decree of ita possideatis (as you possess, so you may possess), which was an interim measure, was briefly referred to as uti possidetis, and its aim was to protect the possession of the possessor by maintaining the status quo against an adversary. Dugard 2006 discusses how over the years the concept of uti possidetis was applied to international law through the works of western European scholars. To understand the reasons for existing state boundaries in South America, Parodi 2002 discusses two different forms of uti possidetis, namely, uti possidetis iuris (de jure, legal possession) and uti possidetis de facto (effective possession). It is the latter principle that has Roman ancestry. Bluntschli 1895 criticizes the direct usage of uti possidetis within international law. The author argues that, unlike in Roman law, uti possidetis in international law is linked to territorial sovereignty, which was not limited to recognizing possession but rather to fixed status. The application of uti possidetis was heavily relied upon in international law in situations involving the termination of a war. This is clear in the works of western European scholars such as in Phillipson 1916. The principle of uti possidetis also became the basis for negotiation of peace treaties in postwar situations; hence, it was used to mean status quo postbellum. This aspect is discussed in the classic works de Vattel 1758 and Wheaton and Phillipson 1916. To a large extent in the past, uti possidetis validated the use of force, because peace treaties fixed the status of conquered territories. However, with the adoption of the UN Charter in 1945, uti possidetis no longer served as a justified principle to seal title to territory acquired by conquest. Publicists such as William Edward Hall (Hall 1895) applied uti possidetis to international boundaries in cases in which territory was not acquired through war but through occupation. Oppenheim 1905–1906 is a classic work that discusses the first actual usage of uti possidetis in determining boundaries, namely, at the time that the Latin American states proclaimed their independence from Spain (1810–1821). The principle of uti possidetis was also used to resolve border issues in Latin America relating to territorial disputes between Portuguese Brazil and neighboring states.

  • Bluntschli, Johann Caspar. Le droit international codifié. 5th ed. Paris: Guillaumin, 1895.

    This classic text discusses general public international law. In the context of the possession of territory at the conclusion of peace, the author discusses international law on the basis of uti possidetis, namely, that the possessor of territory acquires sovereignty of the territory it occupies and that this sovereignty creates the foundation of the new public order. However, the author criticizes this position (article 715).

  • de Vattel, Emmerich. The Law of Nations or the Principles of Natural Law. Leiden, 1758.

    This classic text on international law discusses the subject of peace treaties at length and states that, after the end of a war, each belligerent state shall maintain “the condition in which affairs stand at the time of the treaty.” The author also discusses whether the peace treaty is concluded with the belligerent power based in an actual possession. Available online.

  • Dugard, John. International Law: A South African Perspective. 3d ed. Johannesburg, South Africa: Jute, 2006.

    Provides a fresh perspective in understanding international law in the South African context, keeping in view its history. It also provides an understanding of international law as applied to South African municipal law. This text also discusses how, during the initial years after the birth of international law, it was very much influenced by Roman law, to the extent that jurists equated sovereignty with the ownership of private property as a mode to acquire territory in international law.

  • Hall, William Edward. A Treatise on International Law. 4th ed. Oxford: Oxford University Press, 1895.

    A classic text on international law that discusses uti possidetis and is based on the concept of “actual possession”; played a significant role in legalizing the acquisition of territories by the colonizing powers of Europe and also was used to delimit boundaries between the adjacent proprietors. The principle was extended to delimitation of the coast that bears some reasonable proportion to territory that was claimable by virtue of possession.

  • Moore, J. B. Costa Rica Panama Arbitration: Memorandum on Uti Possidetis. Rosslyn, VA: Commonwealth, 1913.

    Represents an authoritative view on the principle of uti possidetis in a dispute between Costa Rica and Panama, which was vested in the Treaty of Union, League, and Confederation of 1825, signed between the United Provinces of Central America and the Republic of Colombia. This work also discusses the origins and meaning of uti possidetis generally, as well as its application to international boundaries in cases concerning Latin America and Spanish America.

  • Oppenheim, Lassa. International Law: A Treatise. Vol. 1, Peace. London: Longmans Green, 1905–1906.

    This classic work is a major contribution to international law and discusses its various aspects and significant periods.

  • Parodi, Carlos A. Politics of South American Boundaries. Westport, CT: Greenwood, 2002.

    Provides a critical political perspective of South American territorial boundaries as forms of instruments to impose order. Also includes an extended discussion of the Ecuador-Peru boundary dispute of 1810 and the role of the uti possidetis principle. An interesting discussion on uti possidetis de facto is provided in showing how in the context of South America “it gave priority to conquest or settlement over treaties or legal documents to determine the boundaries” (p. 6).

  • Phillipson, Coleman. Termination of War and Treaties of Peace. London: Sweet and Maxwell, 1916.

    This classic text discusses various means to terminate wars and also discusses the nature of peace treaties and their drafting.

  • Wheaton, Henry, and Coleman Phillipson. Wheaton’s Elements of International Law. 5th ed. London: Stevens, 1916.

    This fifth edition of Wheaton’s work is revised heavily by Phillipson, who added about two hundred pages. A classic work on general international law that discusses sources, subjects, absolute rights of states, and rights of states in peace and war. This work relates uti possidetis with the treaty of peace and argues that uti possidetis served as the basis of every “treaty of peace” unless a contrary intent was expressed (p. 807). Digital copy available online.

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