When the rulers of the Tang dynasty (618–906) unified China in the early seventh century, the energies and wealth of the nation proved strong enough not only to ensure internal peace for the first time in centuries, but also to expand the Chinese realm to include large portions of neighboring lands such as Korea, Vietnam, northeast, central, and southeast Asia. The Tang became a great empire, the most powerful and influential of its time any place in the world. Flourishing trade and communication transformed China into the cultural center of an international age. Tang cities such as the capital of Chang’an (modern Xi’an), the eastern terminus of the great Silk Road, were global hubs of banking and trade as well as of religious, scholarly, and artistic life. Their inhabitants, from all parts of China and as far away as India and Persia, were urbane and sophisticated. Tang society was liberal and largely tolerant of foreign views and ideas; in fact the royal family of Tang, surnamed Li, was of non-Han Chinese origin (perhaps originally from a Turkish-speaking area of Central Asia), and leaders of government were drawn from many parts of the region. Government was powerful, but not oppressive; education was encouraged, with the accomplished and learned well rewarded. Great wealth was accumulated by a few, but the Tang rulers saw that lands were redistributed, and all had some measure of opportunity for material advancement. This was also a time when many women attained higher status at court, and a greater degree of freedom in society.