Today we are connected to people all over the world by air routes,boats,phone lines,trains,and the Internet.We can easily communicate with people in distant lands by phone or email;we can buy foreign products with the click of a button.However,it may be surprising to note that in some parts of the world,the period over 500 years ago from 1000 to 1500 A.D.,was also a time of extensive long-distance travel,cross-cultural exchange,and international trading activity.