Hmm well I donot see the timeline.
        
             
        
        
        
Silk Road in Western Han Dynasty (206 BC–24 AD) From 139 BC to 129 BC, Zhang Qian set out on his journey to the Western Regions twice, pioneering the world-famous route.
 
        
                    
             
        
        
        
Answer:
Explanation:
Over time, its economic and military might waned and along with it, the empire's capacity to seize an opportunity. Add in civil unrest, natural disasters and powerful enemies such as the Arabs, Seljuk Turks, Bulgars, Normans, Slavs, and Ottoman Turks, and you can see why the Byzantine Empire eventually crumbled.