Pu-erh is named after the city of Pu-erh in southwestern Yunnan that became a famous trading center and primary source of tea along ancient trade routes between China and its neighboring areas.
Aged and fermented dark teas came about as a result of transporting teas to rural areas of China's borders, hundreds of years ago. Before transporting tea to these areas, the Chinese would compress the tea leaves into slabs and logs. Traveling on horseback and camel, the teas were exposed to moisture and so began to ferment. It was discovered that this developed and changed the flavour of the tea. And Pu-erh was born.