Here are a few facts about China's claim on the South China Sea. Historical documents show China's explorers had discovered and named the Nansha islands as far back as two thousand years ago. And it's then that China held the in-fact sovereignty over these islands.

Things became complicated after the Second World War broke out and Japan illegally occupied the islands. But in 1946, China took back the Dongsha, Xisha and Nansha Islands and sent military to guard these islands. And the next year, China published a map renaming and showing the location of the Nansha islands.

In 1948, China demarcated its territory in the South China Sea with the nine-dotted line. And in 1983, Beijing published a list of standard names for many islands in the South China Sea. However, Phillipine maps had not laid claim to any of the islands in the South China Sea until the 1970s.