Simplify the following text for a Grade 6 native English-speaking person.
Original: A pro-Ming Dynasty state , it was founded by Koxinga ( also known as Zheng Chenggong ) after the Ming government in mainland China was overtaken by the Manchu-ruled Qing Dynasty .
Simplified: It was a pro-Ming Dynasty kingdom . It was started by Koxinga , after the destruction of Ming government by the Manchu .