There are plenty of Ming/Qing era maps that show that that they claimed the islands as their own
鄭和航海圖 1405
柬洋南洋海道圖 1712
四海總圖 1730
東洋南洋各國沿革圖 1844
Some maps I couldn't find but exist
清直省分圖 1724
皇清各直省分圖 1755
大清萬年一統天下全圖 1767
大清萬年一統地量全圖 1810
大清一統天下全圖 1817
Thanks do Danny T. from CHF for compiling them
Well,the Japanese wanted Taiwan as a prize after the First Sino Japnanese War.
Japan handed those islands back to ROC not to the French showing that the Japanese thought the ROC were the rightful owners.
Furthermore people don't' seem to realize that the islands in Vietnamese maps are completely different from the islands in the Chinese map.
Read 駁斥謊言!越南的黃沙、長沙不是中國的西沙南沙 to see that some Vietnamese maps were fabricated to appear older than they really are.
Even Pham Van Dong recognized Chinese claims,are you going to deny that?
So basically the only leg Vietnamese have to stand on is a colonial mentality if it wasn't for the French,Vietnamese wouldn't even care about them today.
However my view is different from other Chinese PDF members,those islands should be left to mother nature and the oceans should be shared.