The Arrow Incident involved a conflict that began when a Qing Dynasty Chinese national was arrested on the Arrow, a ship that had British registration. Despite the Arrow's dubious status and claims of piracy, the British government supported its use as a justification for military action. This incident heightened existing tensions from the First Opium War, as British officials sought increased trade rights and access to Chinese markets. Under the pretext of protecting their nationals and asserting their treaty rights, British forces launched a series of attacks on Chinese ports, notably Guangzhou and eventually extending to the northern areas including Beijing.

The Second Opium War arose from the frustrations of Western powers, particularly Britain and France, regarding China's restrictive trade policies and failure to follow treaties established in the aftermath of the First Opium War. The Western powers sought to expand their influence and secure greater trading rights. As naval ships bombarded coastal cities and ground troops occupied territories, the war introduced widespread suffering and economic disruption in China. Foreign troops gained access to significant ports, establishing a new order that undermined Chinese sovereignty.

Subsequently, the Treaty of Tientsin was signed in 1856, which granted Western nations unfettered access to Chinese markets, legalized opium trade, and allowed foreign diplomats to reside in Beijing. This starkly shifted the balance of power in favor of the Western countries, leading to further inequities in the region and consolidating foreign control over significant aspects of Chinese governance and economy.