Haha, Tang = Han people, today's Chinatown,in Chinese,it's 唐人街--means Tang people streat, Tang dynasty is still Han people established ,China as early as the Qin Dynasty, 2nd century BC, it has been unified.
QIN SHI HUANG u know ,His expedition to northern Vietnam today, unified text, unit of measure, currency. After the national integration, after the Qin Dynasty, the Han Dynasty began, people began to call themselves the Han people, the south also.
Each dynasty they are with their own people dynastic name calling, call themselves Tang people , Song dynasty--song people, Ming dynasty --ming people, but they call themselves the Han Chinese.
India, the road before the British came, southern is an independent country