There are approximately 10,191 people named Sargent in the UK. Approximately 161 out of every million people in the UKare named Sargent.
"The name derives from the Middle English, Old French "sergent", servant, from the Latin "serviens", present participle of "servire", to serve. The word also developed various specialized meanings, for example, a technical term for a tenant by military service below the rank of a knight, and as the name for any of certain administrative and legal officials in different localities. ... The first recorded spelling of the family name is shown to be that of Edric le Sergant, which was dated 1185, in the "Documents relating to the Danelaw", Lincolnshire, during the reign of King Henry 11, known as "The Builder of Churches", 1154 - 1189." - The Internet Surname Database
From the Lay Subsidy of 1334/5