On October 8, 1856, Chinese officials boarded the Arrow, a Chinese-owned ship registered in Hong Kong flying the British flag and suspected of piracy, smuggling and of being engaged in the opium trade. They captured 12 men and threw them into prison.
France joined British action against China to avenge the earlier execution by Chinese local authorities in Guangxi province of a French missionary, Father August Chapdelaine.
The English and the French joined forces under Admiral Sir Michael Seymour, attacked and occupied Guangzhou in late 1857. It then cruised north to briefly capture the Taku forts near Tianjin in May 1858.
In June 1858 the first part of the war ended with the Treaties of Tianjin, to which France, Russia, and the United States were party. These treaties opened eleven more ports to Western trade. The Chinese initially refused to ratify the Treaties.
In 1859, after China refused to allow the setting up of Foreign legations in Beijing, a naval force under the command of Admiral Sir James Hope attacked the forts guarding the mouth of the Peto river. It was severely mauled and forced to withdraw under the cover of fire from an American naval squadron commanded by Commodore Josiah Tattnall.
In 1860, an Anglo-French force gathered at Hong Kong and then carried out a landing at Pei Tang on August 1, and a successful assault on the Taku forts on August 21. On September 26, the force arrived at Bejing and had captured the city by October 6. These troops later ransacked the Summer Palace and the Old Summer Palace.
The June 1858 Treaty of Tianjin was finally ratified by the emperor Xianfeng in the Beijing Convention on October 18, 1860. The allies demanded the right to embassies in Beijing (a closed city at the time) for Great Britain, France, Russia and the United States. The opium trade was legalised. Christians gained the right to spread their faith and hold property, thus opening up another means of western penetration.