The following article is an excerpt from page 76 of The Wathens of Southern Maryland: Their Genealogy & History. You can find many interesting details like these within the 470 pages of the book, which is available for purchase now! Another recent article about the origins of last names can be found on the Family Tree DNA Blog.
The use of last names, or surnames, began to spread through Europe during the Middle Ages. Originally people were known primarily by their given name, such as "John" or "Mary." As populations grew, however, it became necessary to have a way to distinguish one "John" or "Mary" from another.
One of the earliest forms of last names was the use of patronymics, where a person's last name was based on their father's given name. For example, "John, son of William" might be known as "John Williams." Individuals might also be given a surname based on their occupations or places of origin. A John who worked with metal might be known as “John Smith,” and a John from London might simply be called “John London.” Over time, last names became more fixed and inherited from one generation to the next, becoming an important part of a person's identity and heritage.
There is no shortage of theories about the origin of the Wathen family name. Ancestry, quoting the well-respected Dictionary of American Family Names¸ says the following:
Welsh: possibly from the personal name Gwaiddan which is found as part of placenames in Robeston Wathen near Narberth Pembrokeshire and the nearby Llanwathen (from Welsh llan ‘church’ + Gwaiddon).i
House of Names instead asserts:
Wathen is a name that was carried to England in the great wave of migration from Normandy following the Norman Conquest of 1066. The Wathen family lived in Nottingham, at Whatton. The name of this town derives from the Old English words hvaete, meaning wheat, and tun, meaning settlement or enclosure.ii
The nineteenth century book History of Christian Names presents the intriguing theory that the Wathen surname is instead derived from the name of the 12th century English Cistercian abbot, St. Waltheof, commonly known as St. Walthen,iii a Cistercian monk revered in England. Even if this is not historically accurate, perhaps St. Walthen would nonetheless make a good patron saint of the Wathen family: It seems that John Wathen grew up near Abbey Dore, Herefordshire, England, where he would have lived in the shadow of the ancient Dore Abbey, a former Cistercian monastery. The English St. Walthen may well have been known and revered among Catholics there, and “Walthen” is a spelling variation of the family name both here and abroad.
i “Wathen Family History,” Ancestry (https://www.ancestry.com/name-origin?surname=wathen : accessed 29 May 2023); citing “Dictionary of American Family Names 2nd edition, 2022.”
ii “Wathen History, Family Crest & Coats of Arms,” House of Names (https://www.houseofnames.com/wathen-family-crest : accessed 29 May 2023); citing Mills, A.D., Dictionary of English Place-Names. Oxford: Oxford University Press, 1991.
iii Charlotte Mary Yonge, History of Christian Names, Volume II (London: Parker, Son, and Bourn, West Strand, 1863), 232; digital images, Internet Archive (https://archive.org/details/historychristia02yonggoog/ : accessed 29 May 2023).