On the morning of October 8, 1856, the Arrow, flying the British flag, was lying at anchor opposite the British Factories at Canton (Guangzhou) when her Chinese crew were forcibly removed into Mandarin boats. Her master, Thomas Kennedy, reported the matter to the British Consul, Sir Harry Parkes who, after failing to induce the officers concerned to give up their prisoners, demanded of the Imperial High Commissioner Ye Minchen that the twelve men should be returned publicly to the Arrow, whereupon he would be prepared to join with Chinese officials in investigating any crime of which they might be accused. After obtaining instructions from his superior, Sir John Bowring, the Superintendent of Trade, he presented the Commissioner with an ultimatum requiring within forty-eight hours, under threat of action by the naval authorities, an apology and an assurance of respect for the British flag in future.

Bowring had been unable to arrange a meeting with Ye, who frequently left his despatches for a considerable time unanswered; and his efforts to bypass Canton and get into direct touch with Beijing had been thwarted. He concluded that no alternative remained to the threat or use of force.

On October 23 Admiral Sir Michael Seymour, the Naval Commander-in-Chief, began systematically to capture and dismantle the forts in the Canton River. Next Bowring took the crucial step of widening the British demands to include direct official access to the Chinese authorities in Canton; and when this was refused, Seymour began to shell the Commissioner's official residence and then the city wall. This opened a breach through which a force of seamen and marines made a brief sortie to show they could obtain by force what had been unsuccessfully claimed as of right.

Such measures only served to stiffen Ye's resistance; be, ordered the Cantonese to exterminate the 'English barbarians' but by the end of the year the contest seemed to have reached no result but stalemate. Early in the New Year Bowring's proceedings at Canton came in for some sharp criticism in Parliament and actually led to its dissolution. The ensuing General Election was a triumph for Lord Palmerston who advocated a hard-line approach but the outbreak of the Indian Mutiny delayed the prosecution of the war, and it was not until the very last days of 1857 that a joint Anglo-French force launched an attack on Canton.