}}</ref> {{legenda|#ffcc00|Soy sauce}}{{legenda|#ff6600|Fish sauce}}]]
What's interesting, this kind of sauce was most popular in southern China, Indochina and Indonesia – but not further north, in most of China, Korea and Japan. Why? Well, in the north there was an easier-to-make alternative: the soy sauce. Fish sauce, on the other hand, was also produced in the Mediterranean Sea basin. Manufacture of various kinds of fish sauce (such as ''liquamen'', which was used for cooking, and ''garum'', a table seasoning) was a big business in ancient Rome. I once visited in Barcelona the ancient ruins of a fish-sauce factory, which had stood next door to an ancient winery. Which means that must, which was used to make old-time mustard, was produced right next to fish sauce which wasn't much different from that which , closely related to the ancestor of modern ketchup derives from.
Alas, the technology of fish-sauce production, unlike that of mustard, was gradually forgotten after the fall of the Roman civilization (it did survive somewhat longer in the Byzantine Empire). In Italy, ''garum'' was eventually replaced by another delicacy, made from salted, fermented and pressed fish roe, known as botargo. It wasn't until the Age of Exploration that Europeans could come across fish sauces again.