The Treaty of Tientsin, signed in 1885, concluded the Sino-French War that had erupted over French ambitions in Southeast Asia, particularly regarding Vietnam. The conflict was primarily sparked by disputes over France's colonial aspirations for Annam and Tonkin, as well as China's existing tributary relationships in these territories. The war had begun in 1884 and saw significant military engagements, illustrating the increasing tensions between European colonial powers and the Qing dynasty. The treaty formalized the end of hostilities through multiple articles, leading to significant territorial changes.

As a result of the treaty, China recognized French control over Vietnam, relinquishing its claims and halting its influence in a region it had long regarded as part of its sphere. This shift was indicative of the larger patterns of imperialism of the late 19th century, as European powers expanded their empires at the expense of Asian sovereignty. The treaty not only marked the end of the war but also set the stage for the further colonization of Southeast Asia by France, integrating Vietnam into French Indochina, which would have lasting consequences for both local governance and culture.

The Treaty of Tientsin thus represented a critical juncture for Vietnam, leading to over six decades of French colonial rule, which significantly impacted the culture, economy, and social structures of the region. The ramifications of this treaty continue to resonate in discussions about colonialism and its aftermath in Vietnam and Southeast Asia at large.