As much as enamel flourished worldwide, not all cultures see the individual as a natural focus of art. Western Europe led that aspect of enamel artistry, transferring portrait work to a medium that could not be better suited, or embellishing a personal coat of arms.
Enamels had been produced across Europe for millenia, the Celts were crafting their own before Julius Caesar invaded. Many other European countries developed individual techniques and shared that development, as has always been the case.
France is known as a centre for enamelling, from the 18th Century portrait on the left, back to mediaeval Limoges. Yet progress in Limoges came from Venetian craftsmen, who learnt much of their trade from Islamic culture. So the story goes, a circular exchange of skill through the love of art, enamel is truly international.