The son of Harry Parkes, founder of the firm of Parkes, Otway & Co., ironmasters, he was born at Birchills Hall, near Walsall in Staffordshire. When but four years old his mother died and in the following year his father was killed in a carriage accident. Being thus left an orphan, he found a home with his uncle, a retired naval officer, at Birmingham. He received his education at King Edwards Grammar School.
In 1837 his uncle died, and in 1841 he sailed for Macau, to take up his residence at the house of his cousin, Mrs Gutzlaff. At this time what became known as the First Opium War had broken out, and Parkes eagerly prepared himself to take part in the events which were passing around him by diligently applying himself to the study of Chinese. In 1842 he received his first appointment in the consular service. He accompanied Sir Henry Pottinger in his expedition up the Yangtsze-kiang to Nanking, and after having taken part in the capture of Chinkiang and the surrender of Nanking, he witnessed the signing of the treaty of Nanking on board the British warship HMS Cornwallis in August 1842. By this treaty the five ports of Canton, Amoy, Fuchow, Ningpo and Shanghai were opened to trade.
After short residences at Canton and the newly opened Amoy, Parkes was appointed to the consulate at Fuchow. Here he served under Mr (afterwards Sir) Rutherford Alcock. In 1849 he returned to England on leave, and after visiting the Continent and doing some hard work for the foreign office he returned to China in 1851. After a short stay at Amoy as interpreter he was transferred in the same capacity to Canton.
In May 1854 he was promoted to be consul at Amoy, and in 1855 was chosen as secretary to the mission to Bangkok, being largely instrumental in negotiating the first European treaty with Siam. In June 1856 he returned to Canton as acting consul, a position which brought him into renewed contact with Commissioner Yeh, whose insolence and obstinacy led to the Second Opium War. Yeh had now met a man of even greater power and determination than himself, and when, in October 1856, as a climax to many outrages, Yeh seized the British lorcha Arrow and made prisoners of her crew, Parkes at once closed with his enemy. In response to a strongly worded despatch from Parkes, Sir John Bowring, governor of Hong-Kong, placed matters in the hands of Admiral Sir M. Seymour, who took Canton at the close of the same month but had not a sufficient force to hold it. In December 1857 Canton was again bombarded by Admiral Seymour. Parkes, who was attached to the admiral's staff, was the first man to enter the city, and himself tracked down and arrested Commissioner Yeh. As the city was to be held, an allied commission was appointed to govern it, consisting of two Englishmen, of whom one was Parkes, and a French naval officer. Parkes virtually governed this city of a million inhabitants for three years.
Meanwhile the attack at Taku upon Sir Frederick Bruce led to a renewal of hostilities in the north, and Parkes was ordered up to serve as interpreter and adviser to Lord Elgin (July 1860). In pursuance of these duties he went in advance of the army to the city of Tungchow, near Peking, to arrange a meeting between Lord Elgin and the Chinese commissioners who had been appointed to draw up the preliminaries of peace. While thus engaged he, Mr (afterwards Lord) Loch, Mr de Norman, Lord Elgin's secretary of legation, Mr Bowlby, The Times correspondent, and others, were taken prisoners (September 18, 1860). Parkes and Loch were carried off to the prison of the board of punishments at Peking, where they were separately herded with the lowest class of criminals. After ten days confinement in this den of iniquity they were removed to a temple in the city, where they were comfortably housed and fed, and from which, after a further detention, they were granted their liberty. As retaliation, Lord Elgin burned down the Summer Palace of the emperor.
Towards the end of 1860 Parkes returned to his post at Canton. On the restoration (October 1861) of the city to the Chinese he returned to England on leave, when he was made K.C.B for his services; he had received the companionship of the order in 1860.
On his return to China he served for a short time as consul at Shanghai, and was then appointed minister in Japan (1865). For eighteen years he held this post, and throughout that time he strenuously used his influence in support of the Liberal party of Japan. He was friendly toward the Bakufu's rivals and had some influence in the Meiji government as a result. So earnestly did he throw in his lot with these reformers that he became a marked man, and incurred the bitter hostility of the reactionaries, who on three separate occasions attempted to assassinate him.
In 1882 he was transferred to Peking. While in Peking his health failed, and he died of malarial fever on March 21, 1885.
In 1856 Sir H. (then Mr) Parkes married Miss Fanny Plumer, who died in 1879.