Thanks to this world map that shows the density of people with the surname Casler in different countries, you can get an idea not only of the popularity of the surname Casler in each country but also of the different migrations of people surnamed Casler.
The quantity of people with the surname Casler that we can find in each country can help us discern the origin of the surname Casler, as logic tells us that the place with the most people surnamed Casler will be the country or area of origin of the surname Casler.
