Around 1670, two events caused the growth of VOC trade to stall. In the first place, the highly profitable trade with Japan started to decline. The loss of the outpost on Formosa to Koxinga in the 1662 Siege of Fort Zeelandia and related internal turmoil in China (where the Ming dynasty was being replaced with the China's Qing dynasty) brought an end to the silk trade after 1666. Though the VOC substituted Mughal Bengal's for Chinese silk, other forces affected the supply of Japanese silver and gold. The shogunate enacted a number of measures to limit the export of these precious metals, in the process limiting VOC opportunities for trade, and severely worsening the terms of trade. Therefore, Japan ceased to function as the lynchpin of the intra-Asiatic trade of the VOC by 1685.