What was the Jinghai during the Five Dynasties and Ten Kingdoms period? When to appear, when to disappear!

The sea of tranquility mentioned by the two upstairs is not what lz wants to ask at all. Jinghai was a country located in northern Vietnam during the Five Dynasties and Ten Kingdoms period. It was originally a buffer town of our time in the Tang Dynasty. After the demise of the Tang Dynasty, it became independent. Later, the Northern Song Dynasty was unified, and it was no longer called Vietnam, which eventually led to the fact that Vietnam was no longer the territory of China (briefly occupied in the early Ming Dynasty).

I still have two maps of Five Dynasties and Ten Kingdoms in my hand, both of which can see Jinghai (Annan). Unfortunately, Baidu knows that there is no function of uploading pictures.

Wikipedia information:

"Jinghai is our time, which was established in the Tang Dynasty to manage Jiaozhou (now Vietnam).

Annan was the earliest envoy. In the early years of Gan Yuan, it was changed to Annan Festival, which was in charge of 2 1 state, and in the middle of Xian Tong, it was changed to Still Waters Festival, which was later owned by Qu Yu. In the first year of Kaiping (907), he died, went to Bingshen in July, and Sima Quan stayed with the still water master [1]. It spread to the third generation, and was destroyed by Qi Yan in the late Tang Dynasty and early Changxing (930). "

Qingyuan was also a small country in the Five Dynasties and Ten Kingdoms period, located in southern Fujian. After the destruction of Fujian in the Southern Tang Dynasty (945), Fujian was divided into three parts. Jianting and Wuyue in the Southern Tang Dynasty were built in Fuzhou, while Quan and Zhang were kept by local people and owned by Chen, known as Qingyuan Army and Pinghai Division. In the third year of Taiping and Xingguo (978), the land was returned to the Song Dynasty.