During the 17th Century, a fight was started on the water of the ocean that leads to the bifurcation of the world into Spain and Portuguese. This fight leads to the formation of the law of Seas. The Law of the Sea refers to a body of Public International Law that governs the geographic jurisdictions of coastal States, as well as the rights and duties that States have with respect to the ocean environment and its natural resources.[1] As of now, some of the laws are codified under the UNCLOS (United Nations Convention on Law of Sea) which is also known as the ‘Constitution for the Oceans’.[2] Under the Law of the Sea, states make decisions about their rights and responsibilities regarding the use of the world’s oceans and establish guidelines for the environment, as well as for the management of marine and natural resources. 


Historically, no laws were there on the use of oceans, anyone can use them but no one was interested to laid claim to the ocean as they all are interested in land only especially in the continent of Asia. It is sometimes suggested that the law of the sea began with the papal bull of 1493. The Papal Bull is the document written by Pope Alexander VI that divided the world’s oceans between Portugal and Spain.[3] As no one was interested in oceans, it enables Portugal to navigate freely with armed ships in the sea. Through this, they were gained control over the spice trade and able to make enormous profits. It was actually creating a monopoly overseas as Portugal are the only one who was doing their trade. Therefore, to contest their (Dutch) claim overseas Hugo Grotius came up with the theory of Mare Liberum.


It was first placed on a legal basis in 1604 by Hugo Grotius (father of international law).[4] But his work titled ‘Mare Liberum’ was published in 1609.[5] The basic meaning is an open sea or one can say that freedom of the sea. Hugo Grotius’s theory aims to uphold the Dutch’s right to navigate and commerce with Indians as the sea are ought to be free. Grotius has given two propositions of Mare Liberum which are below:

  1. All property is grounded by occupation: Hugo stated that if there is immovable property then it can be enclosed or if it is movable property then it can be seized but whatever is neither enclosed nor seized will not be considered as the property. Such water of the ocean, therefore, should be free. There shall be no right of anyone on the water of oceans.
  2. Everybody has the Right to occupation: Grotius stated that most things exhaust on continuous or long use and one cannot use them in future but this is not the case with the sea as it cannot be exhausted by navigation or finding. Therefore, everybody has a right to use it as their occupation.

Ultimately Hugo Grotius’s work was mainly aimed at defeating the Portuguese monopoly by saying that it should be free as it is a Common Heritage of Mankind. When Grotius made these arguments, no one was there to answer or revert to him. Therefore, the Portuguese all accepted these and removed their monopoly. But, once the Portuguese left the sea, the Dutch seized it and started their trade for creating their own monopoly over the sea. Basically, a guilt trap was formulated by the Dutch people for the Portuguese and now they are creating a monopoly oversea by forgetting their own principle. 


When the fight was going on between Spain and Portuguese over the claim to the sea. In 1631, John Selden came up with his theory of Mare Clausum to answer the theory of Grotius.[6] The literal meaning of the term ‘Mare Clausum’ is ‘sea is closed’. It means that the sea is under the jurisdiction of a particular country. The country can use the water around its border which is under its jurisdiction and the High Sea is public and free for everyone.  This theory becomes popular and countries were following the same but, the era of the Industrial Revolution takes place. So, more and more nations wanted to explore or develop themselves. Thus, Selden’s work loses its popularity and becomes redundant. With this, the monopoly of trade on seas died and Grotius becomes the hero again. 

UNCLOS, 1982

According to the Mara Liberum principle, water beyond national borders is considered international water, which is open to all but not legally owned by anyone. Therefore, a dispute arises among countries. As the development of science and technology leads to the discovery of minerals, ores and other supplements in the sea that will help the nation to become developed. If the water of the ocean is free for all then powerful countries will acquire all the supplements to become rich then, ‘what will the rest of the countries do?’ Therefore, it was necessary to draw boundaries for a particular nation. Thus, the League of Nations organized a conference at the Hague in 1930. But no agreement was signed because, during the discussion, they decided to extend the maritime domain from 3 to 6 nautical miles but due to the narrowness of the gap and relatively small no. of countries participating in the conference leads to no conclusion of the agreement. Truman further extended American Jurisdiction in 1945 to include all of America’s continental shelf, which went well beyond its territorial waters. They cited the reason that principle of customary international law says that nation has the right to protect its natural resources. Immediately after this, countries like Chile, Peru, and Ecuador covered their Humboldt current fishing Grounds over a distance of 200 nautical miles. 

Later with the birth of the UN, a new attempt was to be made. The International Law Commission draft its final report and submitted it to UNGA in 1956. With the commission report, a UN Conference on Law of the Sea was held in Geneva, Switzerland in 1958.[7] Such convention was attended by 82 states which adopted 4 conventions:

  1. Convention on the Territorial Sea and Contiguous Zone: came into the force on 10 Sep. 1964.
  2. Convention on Continental Shelf: came into force on 10 June 1964.
  3. Convention on the High Seas: came into force on 30 Sep. 1962.
  4. Convention on fishing and conservation of living resources of the High Sea: came into force on 20 Mar. 1966.[8]

But, the UNCLOS (I) didn’t set an exact limit on what part of territorial waters states may control. Consequently, in 1960, the UN organized the 2nd Conference on the Law of the Sea, but no new agreement was reached. A similar issue was raised by Malta to the United Nations in 1967. Thereafter, in 1973, the 3rd UN conference on Law of the Sea was held in New York. So, after 9 years, in 12 sessions, the conference adopted the Law of the Sea Convention in 1982.[9] In contrast to the majority vote of more than 160 states, the result of the conference was reached by consensus.


It has been concluded from the above-stated points that earlier no one was interested in the water of the ocean so the Portuguese started their trade over the water which leads to the birth of the Mare Liberum theory which supports freedom over the seas and to answer the Hugo Grotius’s work, John Selden came up with his work in 1631 i.e., theory of Mare Clausum which supports the closed seas. At that time, Selden’s theory gain popularity but due to the evolution of the Industrial Revolution, it went into vain and gain Grotius’s work became the masterpiece. Both the scholars fight for their theories but in the last, both the theory lost their validity due to evolution of the Science & technology because it leads to the discovery of Minerals, Ores and other supplements. Thus, it was required to make proper boundaries and jurisdiction for each state for use of water in an ocean. Hence, a new Law of Seas was formed i.e., UNCLOS, 1982. 

Author(s) Name: Tanisha Vijayvergiya (Lovely Professional University, Jalandhar)


[1] P.Hoagland and et al, ‘Law of Seas’, 2001, 9780122274305, Ocean Sci., < > accessed 12 May 2022.

[2] United Nations Convention on Law of the Seas (Division for Ocean Affairs and the Law of the Sea, 12 February 2022) <> accessed 12 May 2022.

[3] H. Vander Linden, ‘Alexander VI. and the Demarcation of the Maritime and Colonial Domains of Spain and Portugal’ (1916) Vol. 22, OUP, 1.

[4] John Miller, ‘Hugo Grotius’ (2005) SEP <> accessed 13 May 2022.

[5] Rens Steenhard, ‘Grotius, H., Mare Liberum, 1609’ (2020) PPL <> accessed 13 May 2022.

[6] J.P. Sommerville, ‘John Selden, the Law of Nature, and the Origins of Government’, Historical Journal, 27 (1984), 437.

[7] Arthur H. Dean, ‘The Geneva Conference on the Law of the Sea: What was Accomplished’ (1958) Vol. 52, JSTOR, 607.

[8] House of Lords, UNCLOS: the law of the sea in the 21st century (Cmd 159, 1957).

[9] UNCLOS, (International Tribunal for the Law of Sea) <> accessed 16 May 2022.