From A Dictionary of Surnames by Patrick Hanks and Flavia Hodges, comes the following entry for SEYMOUR:
Seymour English: 1. Norman habitation name from Saint-Maur-de-Fossées in Seine, N France, so called from the dedication of the church there to St Maur (see MOORE 3).
2. habitation name from either of two places in N Yorks. called Seamer, from OE sœ sea, lake + mere lake, pond. Elkwall postulates that the original name in OE was simply Sœ 'the lake', the second element being added when the denotation of the first came to be restricted to a body of salt water. There are also places called Semer in Norfolk, Suffolk, and N Yorks., which have the same origin and may lie behind some instances of the surname.
Vars: Seymo(u)re, Seymer.
Cogn. (of 1): Fr.: Saint-Maur.
A family of the name Seymour, who hold the title Dukes of Somerset, originated in Saint-Maur. Some sources say this was the place in Seine mentioned above, others identify it as Saint-Maur-sur-Loire in Touraine. The family is said to have come to England with the Conqueror, and in 1240 William de Saint Maur held lands in Monmouth. They also held the earldom and dukedom of Hertford, and rose to prominence under the Tudors. Edward Seymour (?1506-52) held high office under Henrey VIII, who was married to Seymour's sister, Jane (?1509-37). He was Lord Protector in the reign of Edward VI, but was beheaded for treason on charges laid by his rival, the Earl of Warwick.
As you can see, there appears to be two origins for the Seymour name. The first is clearly the origin for the ducal line, but the second likely comes from a much more humble origin. The only reason to think that Richard Seymour's name derived from the first origin is the use of the dual wings insignia by Richard's son, Thomas. This proves little, however, as it has never been proven or disproven that Thomas had the right to use the insignia!
A good overview of the Seymours in English nobility can be found on Wikipedia: Seymour Family.
Seymour/St.Maur GEDCOM file (150,611 bytes)
This GEDCOM includes the famous Jane Seymour, who married King Henry VIII, and has people as early as the 10th century. It should be emphasized that most American Seymour's are NOT directly descended from this line - despite the “documentation” presented in such documents as “The Royal and Noble Ancestry of the American Seymours”.
This book was published in 1902 by Kegan Paul, Trench, Trübner & Co., Ltd., London. As I understand it, that publishing company merged with another and is now known as Routledge. I asked for permission to reprint this information here, but they could find no record of the book.
Therefore, I include here the section titled “Origin and Early Days of the St. Maur or Seymour Family (pages 1-18)”
Click on the thumbnails below for a larger version.