Simplify the following text for a Grade 6 native English-speaking person.
Original: Under Qing pressure , Zheng Jing struggled to defend Amoy , Quemoy and the Pescadores islands , which he had eventually lost over the years , mainly due to his minuscule forces which were insufficient to defend from Qing forces .
Simplified: Zheng Jing fought the Qing to defend Xiamen , Quemoy and the Pescadores islands , which he finally lost over the years . His small army army was not big enough to defend the islands from the Qing .