Zheng Zhilong defects to the Qing dynasty after seeing that he has no future in Southern Ming. Despite his father's betrayal, Zheng Chenggong remains loyal to the Longwu Emperor and continues to resist the Qing invaders even after the fall of Southern Ming. He plans to retreat to Taiwan and establish a new base of operations there in preparation for retaking Mainland China from the Qing dynasty. In 1661, Zheng Chenggong's fleet sets sail from Xiamen to attack the Dutch on Taiwan. Nine months later, he defeats the Dutch at the Siege of Fort Zeelandia and forces them to surrender and relinquish their control of Taiwan to him.