[1] Tegg was the son of a grocer, born at Wimbledon, Surrey, on 4 March 1776, and was left an orphan at the age of five.
He ran away, sold chapbooks at Berwick, and spent time at Newcastle where he met the wood engraver Thomas Bewick.
In London he obtained an engagement with William Lane, the proprietor of the Minerva Library, at 53 Leadenhall Street.
He subsequently worked for John and Arthur Arch, the Quaker booksellers of Gracechurch Street, where he stayed until he began business on his own account.
On 20 April 1800 he married, and opened a shop in St. John Street, Clerkenwell, but lost money through the bad faith of a friend.
With his wife acting as clerk, he travelled and bought up duplicates in private libraries, clearing his debts.
He was generally believed to have been the original of Timothy Twigg in Thomas Hood's 1834 novel Tylney Hall.