Reginald de Seinesberia fl.1186

Google the history of the Sainsbury surname and you'll run across the claim that the first instance is in the Pipe Rolls of Gloucestershire. For example:

The first recorded spelling of the family name is shown to be that of Reginald de Seinesberia, which was dated 1190, in the "Pipe Rolls of Gloucestershire".

Read more: https://www.surnamedb.com/Surname/Sinisbury#ixzz6uKTI4FIn

However, it's unclear if this example really is a surname (passed down to children) or simply a by-name to indicate that the Reginald in question lived in "Seinesberia" (likely modern-day Saintbury).

But for the record, here's how the 1914 edition of those pipe rolls describe the entry in question:

A curious entry tells us how a man [Reginaldus de Seinesberia] was amerced [i.e., fined] twenty marcs because he refused to marry (renuit) Hasculf Musard's daughter (p. 121), for whose board and clothing £2. 3. 4. (tenpence a week) was allowed by the King as Hasculf's fief was in ward (p. 109). 

And here's the original Latin entry from page 121 of this edition of the pipe rolls:

It's clear that Hasculfi's surname was Musard; but unclear whether "de Seinesberia" is anything more than Reginald's hometown.

Source: Pipe Roll Society. (1914). The great roll of the pipe for the thirty-second year of the reign of King Henry the Second: A.D. 1185-1186. Publications of the Pipe Roll Society. Vol. 36. London: St. Catherine Press. https://archive.org/details/hists59413167/page/n168/mode/1up