In the article “From the East Sea to the U-shape Line”, researcher Nguyen Dinh Dau clarified that in ancient maps of Chinese people; the East Sea was named Giao Chi Sea, Great East Sea or Southeastern Sea.


From this aspect, a question emerges. Why the Giao Chi Sea (14th century) was mistakenly called by Western people as the South China Sea as today? We would like to introduce the follow-up article by researcher Nguyen Dinh Dau to answer this question.

From the utmost antiquity to the 14th century, ancient people thought that the globe had only three continents: Europe, Asia and Africa.

Perhaps the pioneer for this is Greek geographer Ptolemeo who drew the world map with three continents from the South Pole to the North Pole, from the East to the West. These continents accounted for most of the globe and the remaining area for oceans was not significant. Western geographers and cartographers based on this to gradually improve the world map.

Errors at the beginning


In 1492, Christophe Columbus, a Spanish navigator, believed in maps of his time, believed that he could reach India after crossing the Atlantic Ocean. When he arrived in the New World continent (America), he believed that this was India and called the aboriginals as Indian (Indien). This wrong name still exists until now.


In 1497, a Portuguese navigator - Vasco de Gama (1469-1524) commanded a powerfully commercial crew to India by taking a roundabout route through Africa, going upward and turning right to the Indian Ocean. On May 20 1498, the crew arrived in Calicut, after ten months in the sea.

The name India was very attractive in the ancient and medieval ages. Christophe Columbus headed to the west to look for India but he discovered America, and Vasco de Gama headed to the east to look for India and discovered the civilized East Asia.

In the 16th century, Portuguese navigators sailed to the north through the coast of Vietnam to survey China and Japan. They occupied China’s Macau and set up the largest commercial firm there in 1557. Everywhere they passed, they made economic surveys and mapped with longitude and latitude.

The map of Indochina peninsula was made again to the reality to correct the Southeast Asia which was mapped wrongly in maps that had been used popularly before. This peninsula was called Presqu'ile de l'Inde delà le Ganges (Indian peninsula off the Ganges River). Therefore, most of Western maps in the 16th, 17th and 18th centuries noted this part as India Orientalis. There was no map that called it the China Sea (Mer de Chine).

Paracel and Spratly Islands of Vietnam

At that time, the sea between Vietnam’s coast and the Paracel Archipelago (including both Hoang Sa or Paracel and Truong Sa or Spratly Islands) was noted as the Giao Chi Bay near China (Golfe de la Cochinchine) on Western maps.

Cochinchine was the names of Giao Chi (Cochin) and Qin country (Chine) in Chinese characters. Western people read them differently and noted by Latin characters: Giao Chi (or Vietnam) became Cauchy, Cochi or Cochin while Qin became T’sin, Cin, Chine or China.

The country of Cochin (Giao Chi) had the same name with India’s Cochin town and Portuguese noted Cochin as Cochinchina (Giao Chi near Qin country-China) to distinguish it. Cochin is the subject, China is object. China became the name of Zhonghua.

In 1525, Portuguese navigator Diogo Ribeiro discovered the great Pracel Archipelago (including Paracel and Spratly) amid the East Sea. He defined that this archipelago belonged to Cochin (Giao Chi or Vietnam today) so he noted Giao Chi’s coast (in Vietnam’s central province of Quang Ngai today) as Pracel coast (Costa da Pracel) [3].

In the 19th century, people knew that the Paracel Archipelago include small islands located scattered from the north to the south. In the north, they are called the Paracel (Hoang Sa) Archipelago and the Spratly (Truong Sa) Archipelago in the south. The East Sea that surrounds these archipelagos was not called the Cochinchina Sea (Giao Chi Sea) anymore, but it was mistakenly noted as China Sea (using the object – china - and leaving out the subject – cochin). In the 20th century, the name of China Sea became popular.

Perhaps from that error, China confirms the Giao Chi Sea or East Sea as its sea, including islands in that sea. In 1947, the government of the Republic of China made claims over the sovereignty of 80 percent of the East Sea with the U-shape line, including 11 interrupted dots. In 1949, the government of the People’s Republic of China continued this misunderstanding by making similar claims. In 2009, China submitted to the United Nations a map with its waters bordered by the groundless U-shape line, which has been strongly protested by many countries for its violation of the UN Convention on the Law of the Sea (UNCLOS). 

The mistakes in noting geographic names caused many problems, and problems will continue and become more complicated if that misunderstanding is not solved.

Nguyen Dinh Dau

(Source: VietnamNet Bridge)