An said he found many valuable documents from the Nguyen Dynasty in his house, which used to be a temple dedicated to Princess Ngoc Son, daughter of King Dong Khanh and sister of King Khai Dinh.

The papers have been collected and secretly preserved by previous generations, he said.

The official document mentioning Vietnam’s ownership of the archipelago is dated September 27 of the 13th year of King Bao Dai’s reign, or February 15, 1939.

The paper was typewritten in Vietnamese, announcing that a unit of soldiers was awarded honor medals on February 10, 1939 for building guard stations on the Hoang Sa Archipelago.

Mandarin Pham Quynh sent the document to King Bao Dai, who then approved and signed it.

“The award took place on February 15, 1939, more than one month before Japan announced it took over the archipelago on March 31, 1939 and nearly seven months before World War II broke out,” said Dr. Nguyen Nha.

“It proves that the archipelago has belonged to Vietnam for a long time.”

Nha has been the most prominent activist in fighting for Vietnam’s sovereignty over the Hoang Sa and Truong Sa archipelagoes off the central coast, also known as the Paracel and Spratly islands respectively.

“The authorities must make the best use of the official document since it shows the country’s sovereignty over Hoang Sa,” An said.

Reported by Bui Ngoc Long