In the 19th century, the city walls still protected a circuit of but embraced much vacant ground. The bay began to attract Jardines' and Dents' opium ships from 1832. Following the First Opium War, Governor Henry Pottinger proposed using Quanzhou as an official opium depot to keep the trade out of Hong Kong and the other treaty ports but the rents sought by the imperial commissioner Qiying were too high. When Chinese pirates overran the receiving ships in Shenhu Bay to capture their stockpiles of silver bullion in 1847, however, the traders moved to Quanzhou Bay regardless. Around 1862, a Protestant mission was set up in Quanzhou. As late as the middle of the century, large Chinese junks could still access the town easily, trading in tea, sugar, tobacco, porcelain, and nankeens, but sand bars created by the rivers around the town had generally incapacitated its harbor by the First World War. It remained a large and prosperous city, but conducted its maritime trade through Anhai.