This name change occurred with, if Ancestry.com is to be believed, my distant ancestor.
Athon
Nothing is known about Athon, whether he was a noble or a commoner.
Athon, Seignieur de Courtenay (change-death)
Courtenay: after the town he fortified
After taking advantage of the succession crisis between heirs of the Duchy of Burgundy, Athon made himself the Seignieur of Courtenay.
The House of Courtenay would be the ancestral house of many notable Houses, such as Bourbon, Capet, and Valois.
Sources
- “House of Courtenay.” Wikipedia.