What is this obsession for fish sauce? This isn't Thai or Tagalog. Would think it would be for those languages.
Absolutely, it was like the soy sauce of the ancient world, and apparently where Romans got their sodium intake from. For curious students, here's a quote where Isidore describes garum, from his Etymologiae:
«Garum est liquor piscium salsus, qui olim conficiebatur ex pisce quem Graeci γάρον vocabant; et quamvis nunc ex infinito genere piscium fiat, nomen tamen pristinum retinet a quo initium sumpsit».
[Garum is a salty liquid [made] from fish, which was once prepared with a fish which the Greeks called γάρον [garon]; and although it is now made from an infinite variety of fishes, the original name however is retained from the one adopted initially].