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