The Silk Roads were created when classical empires were established, and the scope of long distance trade expanded, connecting much of Eurasia. Throughout the Classical and post-Classical periods, the Silk Roads provided a way for not only goods to be introduced to new lands, but also ideas, religions and technology. The Silk Roads changed drastically due to expanding empires, new technology and diseases. Although the effects and empires with which the Silk Road was connected changed continuously throughout the Classical and post-Classical period, the thing that remained constant was the trade of spices and goods to and from Asia and Europe, and the Silk Road never lost its importance to the economies of the empires.
The growing empires directly affected the Silk Roads. The growth and spread of empires was a direct result of who had the most control over the routes and what ideas were being spread, for instance religion. When disease decreased much of a population, that empire would stop trade with other nations and focus on interregional trade, until their empire was back up on its feet, and then it would again join in trade on the silk roads. This constantly happened with the introduction of new diseases to empires throughout the end of the Classical period and all of the post-Classical period. One example of this was China, when diseases were brought to its shore from the ships, its population decimated and they stopped trading with vast nations for luxuries and kept the trade within its empire till its economy grew and then they continued in trade throughout the silk road.
The new technology introduced to the Silk Road had the most impact on the trade patterns. Throughout the classical period not many changes in technology occurred, however during the post-Classical, you start to see many new technologies introduced to the Silk Road. Yolks, saddles and stirrups were just some of the new transportation technology developed....