Pistor, in its original meaning as the Latin version of "Baker," was in common use in the 13th and 14th centuries. However, even though most English surnames were adopted by the 13th century, Pistor has become a rare name. There were Pistors in London and other parts of England from an early date, but never very many of them. The more Pistor data I have uncovered, the higher the percentage of persons with that name that appear to be related. It is possible that most of the English Pistors are related.
The attached paper started from the premise that John and Edward Pistor, both of whom died in 1776, were related in some way, particularly in light of John having left mourning rings of a value of a guinea to "Mr. Edward Pistor and Mrs. Pistor of Leadenhall Street."
The bequest by John Pistor in his will of 9 February 1776 to "my cousin Robert Wilby of Boston in Lincolnshire Merchant the sum of twenty Guineas for Mourning" provides a clue to the earlier ancestry of the family. This seemed particularly promising in that the International Genealogical Index lists a marriage on 3 May 1702 at Boston, Lincolnshire, between a Robert Wilby and "Sarah Mrs. Pistor."
The Pistors had a long history in Lincolnshire, having settled at Metheringham by the 1500s. That family bore arms: Argent [i.e., silver or white], on a baker's peel in pale [vertically] sable [black] three manchets of the first, two and one. A baker's peel is a long wooden shovel used to put bread in and out of the oven and thus a reference to the origin of Pistor as "baker." A manchet is a small loaf or cake. A pedigree of this family is found in A.R. Maddison's, Lincolnshire Pedigrees (London, 1904; Harleian Society, vol. 52), at vol. III, pp. 786-87.
Pistor Summary (pdf)
The attached summary includes sketches of:
1. Thomas Pistor of Wragby, Lincolnshire, d. 1658; m. Elizabeth ____, possibly Keyworth
2. William PIstor of Boston, Lincolnshire, d. 1691; m1 Marie Cave; m2 Lydia Burton; m3 Jane Whiting
3. Edward Pistor of Greetwell, Lincolnshire; d. 1702; m. Mary ____
4. William Pistor of St. Mary Alderbury & St. Botolph Bishopsgate, London, (<1679-1732), weaver; m. Hannah Hawkins
5. Benoni Pistor of St. Sepulchre, London (c1685-1761); m1 Margaret Price; m2 Elizabeth Haynes
6. Edward Pistor of Greetwell, Lincolnshire (c1680-1752); m. Catherine Pickles
7. Thomas Pistor of Greetwell & Washingborough, Lincolnshire (1684); m. Elizabeth Pickles
8. John Pistor of St. Dunstan in the East & St. Botolph without Aldgate, London & Walthamstow, Essex (1708-1776), woolen draper; m1 Katherine Johnson; m2 Susannah Bryan
9. Edward Pistor of St. Andrew Undershaft & Leadenhall Street, London (1727-1776), clockmaker; m. Ann Grove
10. Johnson Pistor of St. Botolph without Aldgate, London, Walthamstow, Essex & Bath, Somerset (<1747-<1817), woolen draper; m. Mary Pond (inc. daughters Catharine PIstor, who m. John Gwalter Palairet and Mary Pistor, who m. Thomas Coker Adams)
11. Margaret Pistor (1744-1828), m. Richard Clark, Lord Mayor and Chamberlain of London
12. Edward Pistor of St. Andrew Undershaft & Leadenhall Street, London (1751-1802), clock & organmaker; m. Mary Wenman
13. Elizabeth Pistor of Fleet Street, London (b. c1754); m1 Joseph Wenman; m2 Benjamin Hodgson
14. John Pistor of London & North Molton, Devon (1756-1830); m. Ann ____
15. Henry Pistor of London and Surrey (1767-1844), watchmaker & pocket book maker; m. Amelia Wilmott
16. John Pistor of Wallbrook, Hoxton and maybe Bath, possibly adopted the name John Worthington (1772)
17. Henry Pistor of London (1791-1835), wholesale toy & fancy warehouseman; m. Elizabeth Gravenor
18. Charles Frederick Pistor of London (c1792-1880), artist; m. Ann Coles
19. John Pistor of London (c1790s-1854), baker & dealer in artificial flowers; m. Lydia Huson
20. Henry Edward Pistor of London, Kingston-Upon-Hull, and the Birmingham area (1817-1877), glass & china merchant; m. Mary Ann Blunden
21. Thomas Alfred Pistor of London (1860-1927); m. Emilie Ninea Gregg