Pasteur as a surname originated from an occupation. The surname developed from the Latin word “pastor”, which means “shepherd”. The people who herded sheep were named “Pastor”, then Pastour, Pastre and Pasteur. In German, Pasteur became Pfarrer.
The use of a “family” name or second name started in Western countries at about the turn of the last millennium, 1,000 years ago. As the population grew, it became more difficult for people to know who owed money to whom. If Peter was to actually pay Paul, then it became important to know which Peter owed which Paul. So last names, or descriptive names indicating which Peter or Paul began. Surnames began to be taken up in France and in England just before or about the time of the Conquest, under King Edward the Confessor, who was all ‘frenchified’. Surnames developed through different ways (occupation, location, kinship and nicknames).”
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