The origin of the Bourbon family name is Britain, where the accent is very old-time family.

French surnames were subject to large changes in pronunciation, depending on the region.
The original development of the French language was influenced by elements of other languages.
The French language was influenced by old Germanic words and sounds of barbarian tribes that invaded France after the fall of the Roman Empire. The average Frenchman was influenced by the Italian language during the Renaissance.

Some variations of this surname are: Bourdon, Bourdin, Bourdin, Bourbon and many more.