POTSHERDS and obscure publications: These are at the heart of a detailed list of ‘historical evidence’ being used to justify Beijing’s claim of sovereignty over the entire South China Sea.

The China Daily timeline infographic, republished by Chinese news service Xinhuanet, reaches back as far as the 21st century BC, claiming pearls, shells and turtles from the South China Sea had been presented as tribute to the rulers of the Zhou Dynasty.

Han Dynasty pottery shards dating from 206BC were found on Taiping Island (in the Spratley chain), the graphic claims, while documents dating from as early as 280AD refer to a sea known as “Zhanghai” being mapped and patrolled.

The collection of nine panels goes on to list a series of obscure modern international publications as recognising China’s claims, as well as a selection of 1960s and 70s Vietnamese reference books using Chinese names for some islands and uninhabited reefs and shoals between the two nations.

But China’s ‘nine-dash line’ territorial map also makes a grab for waters also claimed by Taiwan, the Philippines, Brunei, Malaysia and Indonesia.

China insists this contentious boundary is based on historical right: Beijing asserts China was the first to name, explore and use the disputed Spratley and Paracel islands at the heart of rising international tensions in the South China Sea.

China is placing great emphasis on using history to strengthen its territorial claims. In 2014 the nation launched their dedicated archeology research vessel Kaogy-01, specifically designed to scour the disputed territories for any fresh cultural links it can find. Some 200 underwater ‘cultural heritage sites’ have already been identified between the contentious Spratley and Paracel island chains.

Exactly how China’s historic links to what were then uninhabited, worthless sandbanks and shoals trump similar claims of heritage by the Philippines, Vietnam and Malaysia is not specified.

EXPLAINER: What’s got the US spooked over the South China Sea?

The Philippines has previously attempted to debunk Chinese historical claims by pointing out ancient maps — including a 900-year-old rock engraving — demonstrated China had always considered Hainan Island off the mainland coast as being the southernmost point of its borders.

China’s moves also don’t appear to have application under the United Nations’ Law of the Sea. This complex international agreement was drawn up after World War II in part to trump a repeat of nationalistic heritage claims such as those used by the Nazis to justify the “Lebensraum” annexation of nearby German-speaking territories.

Instead, it laid out a formula where the rights to national borders extend 22km out to sea and larger exclusive economic zones reach as far as 370km — both balanced by the location of permanent national landmasses including natural islands (but not artificial structures) as well as continental shelves and the proximity of neighbouring nations.