Since the sixteenth century, Hoang Sa (Paracel) and Truong Sa (Spratly) islands had been acknowledged by Western cartographers and navigators as the territories of Vietnam.

After the victory of the Central Highlands and Hue-Da Nang Campaigns, on April 4, 1975, the Central Military Commission ordered Military Zone 5 and the navy force to liberate islands on Truong Sa (Spratly) archipelago.

A collection of 20 books on Vietnam’s sea and island sovereignty has been released to the public.