An agent; a substitute in mercantile affairs; a commission merchant. (Latin, facio, to do, whence the French facteur, one who does something for an employer.)
Asleep and naked as an Indian lay, An honest factor stole a gem away.
Pope: Moral Essays, Ep. iii. 361.
Thomas Pitt, ancestor of the Earl of Chatham, was appointed by Queen Anne Governor of Fort St. George, in the East Indies, and in 1702 purchased there, for £20,400, a diamond weighing 127 carats, which he sold to the King of France. This gem is still called the Pitt diamond. Pope insinuates that Pitt stole the diamond. This is not exactly true. He obtained it for a price much below its value, and threatened the thief with exposure if he made a fuss about the matter.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894