Origin of the name Thurlby
Surnames as we know them today were first assumed in Europe from the 11th to the 15th centuries. They were not used in England and Scotland before the Norman Conquest of 1066 and were first found in the Domesday Book. The employment of a second name, a custom introduced by the Normans, who themselves had not long adopted it, became in the course of time, a mark of gentle blood. It was deemed a disgrace for a gentleman to have one single name, as the meaner sort had. It was not until the reign of Edward II (1307-1327), that the practice became general amongst all people. These names were adapted according to fairly general principles and can be generally divided into four classifications.
Local names are taken from places of origin (as is the case with the surname Thurlby).
Occupational names denote the trade or profession of early users.
Nicknames describe mental and physical characteristics, complexion, clothes etc..
Patronymic was the method of taking the first name of the father as the last name of the son.
Although the name, Thurlby, appears in many references, from time to time the surname was spelled differently, and these changes in spelling frequently occurred, even between father and son. Scribes recorded and spelled the name as it sounded. Typically a person would be born with one spelling, married with another, and buried with a headstone which showed another. All three spellings referred to the same person.
There is some evidence that "Thurlby" is derived from the Scandinavian name "Tuyrolf" (Tuyrolf´s Village) with "by" the suffix for fortified village.