Thomas Corbyn was born in 1711 in Worcestershire, where both his parents were Quaker ministers. He moved as a teenager to London, where he died in 1791. He came from a long-lived family.
His parents were John & Candia Corbyn of Worcester, who married in 1696. Candia, daughter of John & Celicia Handley, born at Pontypool in Monmouthshire, died 28 April 1767 and her remains were decently interred in Friends' burial-ground at Worcester 3 May; aged 96, and a minister 73 years. John Corbyn, minister at Worcester, was convinced of the blessed truth about the eighteenth year of his age; about the thirty-fourth year of his age he came forth in a public testimony; he departed this life 30 January, and was interred 1 February 1752 in the Friends' burial ground in Worcester, in the eighty-third year of his age. Their eldest son John Corbyn was born 1700 and died 1785; second son Samuel Corbyn was born 1706 and died 1799 - he was a linen-draper in Worcester. Their daughter Hannah, born 1713, married ? Palmer and their daughter Candia, born 1714, married John Burlingham 9 December 1743 - both women were still living in 1796.
Since the Quaker John Corbyn (1670-1752) of Worcester gave his three sons the same names as three of the six sons of John Corbyn (1604-1671) of Eymore in Worcestershire, there is likely a family relationship.
By 1742, Corbyn had served his long apprenticeship (which began in 1728) followed by six years as a journeyman in the employ of Joseph Clutton, a London apothecary with a substantial domestic wholesale business. Slowly dying of consumption, Clutton put Corbyn in charge of the firm. In return Corbyn gained the freedom to engage his own money in trade, anywhere outside England. On the death of Clutton's son Morris in 1754, Corbyn was able to acquire sole possession of both sides of the business, at home and abroad.
In 1752 Thomas Corbyn married Sarah Garrett, a Quaker from Colchester, Essex. They lived in Leytonstone and later in Kentish Town, where he was "a good practical gardener". Their first child, Elizabeth, was born 4 December 1752, followed by Sarah on 16 August 1754. A son John (named for his grandfather) was born about 1758. He was convicted of embezzlement at Middlesex Court on 18 February 1814 and imprisoned for 6 months. In 1822 he was described as druggist of Holborn when his wife Hannah died on July 20 at Walthamstow in the 62d year of her age. In 1841 he was living alone in Walthamstow. Elizabeth married banker John Lloyd (6 Jan 1750/51 - 22 Jan 1811) on 20 April 1779 and died in January 1839, having had 7 sons and 3 daughters. Sarah married solicitor Richard Phillips (1756-1836) on 11 November 1790. For the first 20 months of their marriage this couple resided at Thomas Corbyn's town house in Barthlomew Close.
He is listed in several London business directories (such as The Universal Pocket Companion. 3rd edn., 1760, London) with Occupation as chymist, science/invention; and Address as opposite Bromley Street, High Holborn, London.
Benedict Arnold, later to achieve infamy as a traitor General during the American Revolution, entered business in 1761 and the following year visited London, where he acquired stock on credit. He set up shop on Chapel Street in New Haven, CT, under the sign 'B. Arnold Druggist/ Bookseller &c./ From London/ Sibi Totique', across the Green from Yale, to whose students he sold books. Arnold went bankrupt, owing some £16,000 when his business failed in the summer of 1766. Thomas Corbyn was Arnold's principal creditor and represented Arnold's creditors from the London end. To New York merchant Bernard Lintot fell the unenviable task of dealing directly with Arnold. After a great deal of trouble he eventually got Arnold to agree to pay ten shillings in the pound plus interest, only to find him reneging on the deal a month later. Arnold eventually made settlement in September 1770. As for the remaining half of the debt, still outstanding, it had probably not occurred to Arnold that his past debt would still await him when he came to London after his treason. In 1782, after Arnold had settled in London, Corbyn's partner John Brown raised the subject of Arnold's outstanding debt.
Thomas Corbyn was prominent among London Quakers. His somewhat dictatorial pronouncements led to his being referred to by some fellow religionists as "Pope Corbyn". Both he and his son John were among the 273 Quakers who, at the Yearly Meeting on June 16, 1783, signed the First Petition to Parliament for the Abolition of Slavery, his being the fourth signature.