Because they were different from other city-states
I believe that is the correct answer
Foreigners would Be the correct answer I believe
Han Dynasty was achieving in art, technology, and polotics. It was the longest dynasty to last in China. It's technology spread into the great world and had created pulleys and wheelbarrows to pull and push heavy objects easier. They had also created the first newspaper that could be printed which became the evolution of our technology today.
Best bet is political if not economic