Why is Tang Dynasty so glistening and historic?

The culture reached its peak during that dynasty.
Tang poems are very famous since then on. The architecture during that time was imitated by many countries in Asia and now you can see many architectures of Tang Dynasty in Japan and so on. The intercultural communication between countries flourished. The country sent many people to learn and spread the country's culture and accepted many foreigner coming to China.
These are all I know and I hope these can help you.