Between September 1842 and August 1843, Parkes served as a clerk under Karl Gützlaff, who was appointed as a civil magistrate in Zhoushan after the British occupied the island.

However, as there was a delay in the opening of Fuzhou port, he was instead reassigned to serve at the consulate in Canton and as an assistant to the Colonial Secretary of Hong Kong.

In March 1845, he and Rutherford Alcock (the British consul in Amoy) were transferred to Fuzhou, where they were attacked on 4 October by Chinese soldiers, who threw stones at them.

In June 1846, he assisted Alcock in securing $46,163 from the Chinese authorities in Fujian as compensation for British property looted and destroyed during a riot.

He exchanged the ratified Bowring Treaty in Bangkok on 5 April 1856 and arrived in Canton in June to serve as the acting British consul during Alcock's absence.

[2] Parkes's position as the acting British Consul in Canton brought him into renewed contact with Ye Mingchen, the Qing-appointed Imperial Commissioner and Viceroy of Liangguang.

Further, Captain Kennedy admitted in his deposition to Parkes of 9 October 1856 that he had been breakfasting in another vessel called the Dart at the time of the incident, an account that his fellow diners, John Leach and Charles Earl, corroborated.

According to a local newspaper, the master and crew of a nearby Portuguese lorcha corroborated Chinese officers' account that no flags had been flying on the Arrow when it was boarded by the marine police.

The British did not have sufficient troops to permanently occupy Canton, but they kept warships on the Pearl River and positioned their artillery to overlook the city.

Parkes, who was attached to Admiral Seymour's staff, was part of the group of Anglo-French representatives who delivered an ultimatum to the Qing officials on 12 December.

"Ye was my game," said Parkes, and finally found what a report called "a very fat man contemplating the achievement of getting over the wall at the extreme rear" of the administrative office.

On 25 June 1859, with the British attack on the Taku Forts by the Hai River in Tianjin hostilities between the Anglo-French and Qing sides resumed.

Upon learning that the imperial commissioners did not hold plenipotentiary powers from the Xianfeng Emperor as they initially believed, the British and French troops then advanced further towards Tongzhou near the Qing capital, Beijing (romanized as "Peking" at the time).

Parkes and a delegation – whose members included Henry Loch (Lord Elgin's private secretary) and Thomas William Bowlby (a journalist for The Times) – travelled ahead of the Anglo-French army to negotiate with the Qing officials in Tungchow on 14 and 17 September.

After receiving a hostile response, he and the delegation attempted to head back to the British headquarters, but were arrested by Qing soldiers under the command of the general Sengge Rinchen.

On 29 September, as ordered by Prince Gong (the Xianfeng Emperor's brother), Parkes and Loch were transferred out of the prison to more comfortable living quarters in a temple, where they were pressured to intervene in the negotiations between the Anglo-French and Qing sides.

On 8 October, Parkes, Loch and six other members of the delegation were released from captivity – just shortly before the Qing government received an order from the Xianfeng Emperor, who was taking shelter in the Chengde Mountain Resort, for their executions.

On 18 October, in retaliation for the torture and deaths of the other members of the delegation, Lord Elgin ordered the British and French troops to burn down the Qing Empire's Old Summer Palace in the northwest of Beijing.

Following the signing of the Convention of Peking on 18 October 1860, Parkes returned to his post in Canton in January 1861 and managed the cession of Kowloon, Hong Kong to the Crown.

Between February and April 1861, Parkes accompanied Vice-Admiral Sir James Hope on an expedition along the Yangtze River to set up consulates at the three cities and attempt to reach an agreement with the Taiping rebels at Nanjing.

Parkes left England in January 1864 and arrived on 3 March in Shanghai, where he assumed the position of consul which he was previously appointed to on 21 December 1858.

[9] In May 1865, during a trip to the Yangtze ports, Parkes received a notification for him to succeed Sir Rutherford Alcock as "Her Majesty's Envoy Extraordinary and Minister Plenipotentiary and Consul-General in Japan".

[11] During this turbulent Bakumatsu period, Parkes pursued a policy of neutrality between the Tokugawa shogunate and the pro-Imperial forces, hoping for a peaceful resolution to the crisis.

[11] Throughout his 18 years in office, Parkes was instrumental in bringing a large number of British foreign advisors to train the Imperial Japanese Navy and to build modern infrastructure, such as lighthouses, a telegraph system and a railway between Tokyo and Yokohama.

"[13] In 1869, Prime Minister William Gladstone requested a report on washi (Japanese paper) and papermaking from the British embassy in Japan.

"She was a beautiful girl," wrote a friend about her, "tall, well-proportioned, and graceful, her colouring rich and soft, her features expressing sensitiveness and the power of warm emotion; her dark brown eyes full of intelligence and speaking earnestness of purpose.