Thomas Manning was born in Broome, Norfolk on 8th November, 1772, the second son of Reverend William Manning, rector of Brome and subsequently rector of Diss, Norfolk, and his wife, Elizabeth, the only child of Reverend William Adams, rector of Rollersby Norfolk.
Thomas Manning was educated locally and was admitted to Gonville and Caius College, Cambridge in 1790 to study mathematics. Here he made some lifelong friends including Charles Lamb (1775-1834). Manning was very able but did not graduate as he refused to sign the oath of allegiance to the Church of England. Manning continued in Cambridge coaching students and published his Introduction to Arithmetic and Algebra (1796-1798)
Manning became interested in China and the Chinese language and in January 1802, sailed from Dover to stay in Paris where he met and studied with Dr Hagar at the Bibliotheque Nationale. Manning intended to stay in Paris for two years but was detained further due to the Napoleonic conflict with England. He returned to England in late 1804 and studied medicine for 6 months at Westminster Hospital with the intent of gaining an useful skill for his travels.
Manning first thought of trying to reach China overland via Russia but felt that his language skills were insufficient and therefore applied to the East India Company to travel on board one of their boats. He sailed on the Thames in May 1806 arriving in Canton, China, later that year.
Manning lived within the East India Company factory and helped with medical matters and translation. He was frustrated by lack of access to interior China. He joined an expedition to Cochinchina (Vietnam) in 1808. This expedition failed and Manning returned to Canton.
Manning then decided to attempt to reach the interior of China via Tibet. For this purpose he sailed on the Pellen to Bengal. He became known in Calcutta for his flowing beard and native costume. He waited for official permission to travel through Bhutan but in the end set off with one Chinese servant entering Bhutan in September 1811 and Tibet later that year.He travelled with Chinese soldiers and treated their medical ailments. He reached Lhasa in December 1811 and was allowed an audience with the Dalai Lama. However he was not able to continue further inland and was sent back to Calcutta in 1812. From there he returned to Canton where he continued his studies until joining the unsuccessful Amherst Embassy in 1816, after which he set off for England with the Embassy on the Alceste. This was wrecked on 17 February 1817 and he continued on the Caesar. He reached St Helena in July 1817 and was given an audience with Napoleon who was imprisoned on the island.
Manning returned and settled in England. He lived in Italy, wanting to improve his spoken Italian, between 1827-1829. He returned to England and continued to live in Kent until 1838, when after a stroke which disabled his right hand, he moved to Bath to gain better medical attention. He died at Bath on 2 May, 1840 and was buried in Bath Abbey Church.