Final answer:
The Silk Roads were an extensive network of trade routes from Chang'an to Rome, involving many different legs and frequent exchanges of goods among merchants. The precise distance would vary, but it was a journey of several thousand miles that few merchants completed in full, typically trading goods along the way.
Step-by-step explanation:
The Silk Roads were a vast network of trade routes connecting the East and the West, significant for their role in the exchange of goods, cultures, religions, and ideas. The journey from Chang'an to Dunhuang, onto Marakanda (Samarkand), Antioch, and finally to Rome would have covered thousands of miles, varying greatly depending on the specific pathways taken and the geographic and political landscape of the time. This network reached its peak between the fifth and eighth centuries, a time when the Tang dynasty in China and later the Islamic caliphate played prominent roles in its flourishing.
Setting out from Chang'an, the eastern terminus, merchants confronted the Gobi Desert and relied on caravansaries for rest and resupply. Localized trade was the norm, as goods changed hands frequently, increasing in price the further they traveled. When estimating the entire distance, it is essential to understand that it was rare for a single merchant to traverse the entire route. Instead, the trade goods would move through a series of exchanges from East to West.
Moreover, the Silk Roads facilitated not only trade but also cultural exchange, introducing religions such as Buddhism and Islam to new regions. The network began during the Han dynasty, thrived during the Tang dynasty, and saw changing control after the battle at the Talas River between the Tang and Abbasid empires. Through caravans and the perilous journeys of countless individuals, the Silk Roads shaped much of the ancient world's history.