Historical Perspective on Territorial Seas Countries have generally claimed some part of the seas beyond their shores as part of their territory, as a zone of protection to be patrolled against smugglers, warships and other intruders. At its origin, the basis of the claim of coastal States to a belt of the sea was the principle of protection; during the seventeenth and eighteenth centuries another principle gradually evolved: that the extent of this belt should be measured by the power of the littoral sovereign to control the area. In the eighteenth century, the so-called "cannon-shot" rule gained wide acceptance in Europe. Coastal States were to exercise dominion over their territorial seas as far as projectiles could be fired from a cannon based on the shore. According to some scholars, in the eighteenth century the range of land-based cannons was approximately one marine league, or three nautical miles. It is believed that on the basis of this formula developed the traditional three-mile territorial sea limit. By the late 1960s, a trend to a 12-nautical-mile territorial sea had gradually emerged throughout the world, with a great majority of nations claiming sovereignty out to that seaward limit. However, the major maritime and naval Powers clung to a three-nautical-mile limit on territorial seas, primarily because a 12-nautical-mile limit would effectively close off and place under national sovereignty more than 100 straits used for international navigation. A 12-nautical-mile territorial sea would place under national jurisdiction of riparian States strategic passages such as the Strait of Gibraltar (8 miles wide and the only open access to the Mediterranean), the Strait of Malacca (20 miles wide and the main sea route between the Pacific and Indian Oceans), the Strait of Hormuz (21 miles wide and the only passage to the oil-producing areas of the Gulf) and Bab el Mandeb (14 miles wide, connecting the Indian Ocean with the Red Sea)... The claim for 200-nautical-mile offshore sovereignty made by Peru, Chile and Ecuador in the late 1940s and early 1950s was sparked by their desire to protect from foreign fishermen the rich waters of the Humboldt Current (more or less coinciding with the 200-nautical-mile offshore belt). This limit was incorporated in the Santiago Declaration of 1952 and reaffirmed by other Latin American States joining the three in the Montevideo and Lima Declarations of 1970. The idea of sovereignty over coastal-area resources continued to gain ground. As long-utilized fishing grounds began to show signs of depletion, as long-distance ships came to fish waters local fishermen claimed by tradition, as competition increased, so too did conflict. Between 1974 and 1979 alone there were some 20 disputes over cod, anchovies or tuna and other species between, for example, the United Kingdom and Iceland, Morocco and Spain, and the United States and Peru. At the dawn of international law, most maritime States were somewhat preoccupied with claiming that they had sovereignty and authority over quite extensive parts of the ocean. Venice claimed the Adriatic, England the North Sea, the Channel, and a large part of the Atlantic, Sweden the Baltic, and Denmark-Norway all the Northern seas. The State that claimed the seas often rendered a service to all by policing them against piracy; and in return it claimed proprietary rights over them. Reaction to the above claims came in the sixteenth century when, under the Bulls of Pope Alexander VI of 1493, Spain and Portugal claimed to divide the New World between themselves. Spain claimed the whole Pacific and the Gulf of Mexico; Portugal the Indian Ocean and most of the Atlantic, and both excluded foreigners from these vast areas. The other European countries denied the legal validity of the claims of Spain and Portugal. They argued that it was contrary to natural law and elemental principle of international relations to claim the seas and its waters as the private property of one nation. The cry soon emerged that the use of the sea should be common to all nations. Queen Elizabeth I of England in reply to a protest by the Spanish Ambassador against the passage of Drake's vessels on the seas reserved for Spain under the Papal Bull, stated: "The use of the sea and air is common to all. Neither can title to the ocean belong to any people or private persons for as much as neither nature nor public use and custom permitteth any possession thereof..." In 1609, Hugo Grotius, a Dutch lawyer, published Mare Liberum in justification of Dutch resistance to the Portuguese claim, maintaining that the sea was res communes, that is, belonging to all and could not be made the property of any State. The thesis was attacked by John Seldon in Mare Clausum, in which the right of the State to assert its sovereignty over seas adjacent to its territory was placed on the ground of appropriation, dominion, and uncontested use. Grotius, by 1625 in De Jure Belli Ac Pacis, Libri Tres admitted that Mare Liberum might not apply to the adjacent sea, and a successor, Johones Potanus, finally also conceded this. In the course of time a majority of States began to adopt the view that the extent of the State's sovereignty over its adjacent sea should be limited in practice by some notion of effective control. By the eighteenth century this notion of effective control became synonymous with the range of the cannon from shore batteries. The maximum range of such cannon shots was then three miles. Thus what had originally been a practical test of effective control in terms of cannon fire subsequently became crystallised as the test of effective control over a State's claim of sovereignty of its territorial sea. (Fortunately there was no attempt, so it seems, to extend a State's claim when, in the course of time, the force of cannon fire improved in range.) Source: The United Nations Convention on the Law of the Sea: A Historical Perspective http://www.un.org/Depts/los/convention_agreements/convention_historical_perspective.htm