The history isn't entirely clear. Early on, a lot of separators were used, but it seems that in the 18th century, France standardized on the comma, spreading it

The history isn't entirely clear. Early on, a lot of separators were used, but it seems that in the 18th century, France standardized on the comma, spreading it to the rest of continental Europe, while Britain settled on the decimal point. And their spheres of influence pretty much settled the question internationally: https://upload.wikimedia.org/wikipedia/commons/a/a8/DecimalSeparator.svg https://upload.wikimedia.org/wikipedia/commons/a/a8/DecimalS...