One way to trace the parents of your ancestor is by looking at records concerning their apprenticeships. There are two useful books for Gloucestershire Apprentices, both produced in the Gloucestershire Record Series by the Bristol and Gloucestershire Archaeological Society.
They are: ‘A Calendar of the Registers of Apprentices of the City of Gloucester 1595-1700’ edited by Jill Barlow, M.A. and ”A Calendar of the Registers of the Freemen of the City of Gloucester 1641-1838′ transcribed by Peter Ripley and revised and edited by John Jurica.
The first book deals with the apprenticeship registers and has entries such as:
1690 Nov 1 Gwinnett Francis, son of Lawrence, gentleman of Great Shurdington, to Newman, Samuel 7years baker
1680 Apr 12 Gwinnet, Richard, son of George, gentleman of Badgeworth, to Randle, Josiah & Margery, 7yrs baker 2s 6d.
the second line giving the name of the apprentice’s master, the length of time of his apprenticeship, the trade and sometimes the amount paid to the master. At the end of the apprenticeship, the apprentice was entitled to become a freeman of the city.
The second book, listing the Freemen, has entries such as:
1757 Oct 24 Button Gwinnett, son of Sam., clerk
1806 Apr 14 Sam. Gwinnett, writer, son of Chas., victualler
(There is a note that Button was a signatory on the American Declaration of Independence of 1776.)
A man could become a freeman in four ways, by apprenticeship, by patrimony, by purchase or by gift of the city corporation. Although the books, available via Amazon.co.uk, specify the city of Gloucester there are entries for people from the whole county of Gloucestershire as well as a few from elsewhere.