Is the word "once" in "Afang Palace Fu" a synonym for ancient and modern times? How to translate?

Once the country is destroyed and can no longer be occupied, they will all be transported to Afang Palace. From then on, the tripods were regarded as iron pots, the jade was regarded as stones, the gold was regarded as clods, and the pearls were regarded as gravel. They were all thrown around, and the people of Qin looked at them without feeling pity.

This is the translation of one of the ancient sentences, and I don’t understand it either. But the original meaning is translated as once. I hope you can solve the problem as soon as possible