Because of its proximity to mainland China, as well as its location in a natural harbor, Tamsui quickly became a major fishing and trade port.
The Qing naval patrol also established an outpost in Tamsui in 1808.
In 1862, the Qing government opened Tamsui to foreign trade under the terms of the Treaty of Tientsin, exporting tea, camphor, sulfur, coal, opium, and dyes.
By the mid-19th century Tamsui had become the largest port in Taiwan, boasting a sizable foreign population as well as a British consulate at Fort Santo Domingo.

Canadian medical doctor and missionary George Leslie Mackay arrived in Tamsui on 9 March 1872, proceeding to establish Taiwan's first hospitals in Western medicine and formal educational facilities, including Oxford College (now part of Aletheia University), the oldest European-style higher-education institution in Taiwan by some measure.

During the Sino-French War the French attempted an invasion of Taiwan during the Keelung Campaign.
Liu Mingchuan, who was leading the defence of Taiwan, recruited Aboriginals to serve alongside the Chinese soldiers in fighting against the French.
The French were defeated at the Battle of Tamsui and the Qing forces pinned the French down at Keelung in an eight-month-long campaign before the French withdrew.

In 1884, the harbour of Tamsui was blockaded by the French Navy under the command of Admiral Amédée Courbet, during the Sino-French War.
The French were defeated at the Battle of Tamsui by the Chinese and, according to traditional accounts, with the divine assistance of the Goddess Mazu.
Because of its proximity to mainland China, as well as its location in a natural harbor, Tamsui quickly became a major fishing and trade port. The Qing naval patrol also established an outpost in Tamsui in 1808. In 1862, the Qing government opened Tamsui to foreign trade under the terms of the Treaty of Tientsin, exporting tea, camphor, sulfur, coal, opium, and dyes. By the mid-19th century Tamsui had become the largest port in Taiwan, boasting a sizable foreign population as well as a British consulate at Fort Santo Domingo.
Canadian medical doctor and missionary George Leslie Mackay arrived in Tamsui on 9 March 1872, proceeding to establish Taiwan's first hospitals in Western medicine and formal educational facilities, including Oxford College (now part of Aletheia University), the oldest European-style higher-education institution in Taiwan by some measure.
During the Sino-French War the French attempted an invasion of Taiwan during the Keelung Campaign. Liu Mingchuan, who was leading the defence of Taiwan, recruited Aboriginals to serve alongside the Chinese soldiers in fighting against the French. The French were defeated at the Battle of Tamsui and the Qing forces pinned the French down at Keelung in an eight-month-long campaign before the French withdrew.
In 1884, the harbour of Tamsui was blockaded by the French Navy under the command of Admiral Amédée Courbet, during the Sino-French War. The French were defeated at the Battle of Tamsui by the Chinese and, according to traditional accounts, with the divine assistance of the Goddess Mazu.
Tamsui District