signed a trade agreement with Zheng Taiwan. However trade with the British was limited because of the Zheng monopoly on sugar cane and deer hide as well as the inability of the British to match the price of East Asian goods for resale. Zheng trade was subject to the Qing sea ban policy throughout its existence, limiting trade with mainland China to smugglers. Peace negotiations After Zheng Jing's forces were ejected from the mainland, the Qing tried to win over Zheng through negotiation. In 1667 letters were sent to Zheng Taiwan to negotiate their surrender. Zheng Jing declined the offer. Zheng emphasized that Taiwan had never been part of China and that he wished to establish relations with the Qing based on a model similar to a foreign country. However the Ming loyalist Zha Jizu noted in 1669 that Zheng Jing continued to use the defunct Ming dynasty's calendar. He never gave up on aspirations for power on the mainland and later attacked the Qing dynasty during the Revolt of the Three Feudatories, taking settlements on the coast. General Kong Yuanzhang, who had defected to the Qing, personally visited Zheng Jing in Taiwan in November 1667. He returned in December with nothing but reports of gracious treatment and gifts of precious items. In 1669 the Qing offered the Zhengs significant autonomy in Taiwan if they shaved their heads and wore their hair in the Manchu style. Zheng Jing declined and insisted on a relationship with the Qing similar to Korea. After the military conflict with Zheng during the Three Feudatories revolt, the Kangxi Emperor made clear that he considered all the southern Fujianese living in Taiwan to be Chinese, unlike the Koreans, and that they must shave their heads. Revolt of the Three Feudatories In 1670 and 1673, Zheng forces seized tributary vessels on their way to the mainland from Ryukyu. In 1671, Zheng forces raided the coast of Zhejiang and Fujian. In 1674, Zheng Jing took advantage of the Revolt of the Three Feudatories on the mainland and recaptured Xiamen and used it as a trading center to fund his efforts to retake mainland China. He imported swords, gun barrels, knives, armours, lead and saltpeter, and other components for gunpowder. Zheng made an alliance with the rebel lord Geng Jingzhong in Fujian, but they fell afoul of each other not long afterward. Zheng captured Quanzhou and Zhangzhou in 1674.