The Violet Fox: The BeastWorld Prophecies After Bai Qingqing
Fruits and nuts had a small, natural, amount of salt within them, but once they were relying on winter stashes of food, additional jarred salt was needed to get through the cold snap.
For Shuule's entire life, the Second Great City had a monopoly on the salt market, as they had figured out how to make it rather than being at the mercy of the Merman tribe, which was more or less extinct now. Traditionally, the city would visit other villages, and trade salt for females - and their mates, which is how the city had expanded so fast.