Korean history - Balhae

In AC. 698, 30 years after Goguryeo collapsed, Dae Joyoung, a general of Goguryeo, who continued to resist the Tang, founded the Balhae nation with the migrants of Goguryeo and parties of Malgal. However, today, China is distorting our history of Balhae, and claiming that they were minority race in their empire.China asserts that Balhae was not an independent country but a local government of Dang because the King of Balhae was a vassal of the King of Dang. But this is not true. You can see the reasons through this video