jan 1, 198 BC - 129 BC Parthians conquer Mesopotamia. The Silk Road to China is now controlled by the Parthians. This is important because this event would have been a massive impact on trading for the Seleucid Kingdom. One of the power they had is now taken by the Parthians, which will make the kingdom weaker. Because they were in the Mesopotamia connecting Mediterranean to Asia, they were in power of trading. However, as the Parthians now has the control of the Silk Road, they would have no power.
Added to timeline:
Date:
jan 1, 198 BC
Now
~ 2225 years ago