On the Taiwanese mainland, across from the sandbank where the VOC built fort Zeelandia in 1624, a Chinese-Dutch settlement soon developed. Its name, Saccam, probably derives from the language of the Siraya, the aboriginal group inhabiting this area. When the Chinese under VOC rule revolted in 1652, Saccam was partly destroyed in the revolt. For this reason Fort Provintia was built in the settlement in 1653.

When the Chinese warlord Koxinga invaded Taiwan in late April 1661, Saccam was the first settlement he conquered. After he succeeded in driving the VOC off Taiwan, Saccam would become the capital of the Tungning kingdom founded by him.