Yunnan

Yunnan is a province of China, located in the far southwest of the country spanning approximately 394,000 square kilometers (152,000 sq mi) and with a population of 45.7 million (2009). The capital of the province is Kunming. The province borders Myanmar, Laos, and Vietnam. The province is in a mountainous area, rich in natural resources.

Given its international borders and its relatively remote location, Yunnan's place in China has been murky at times throughout the country's history. Yunnan served as a redoubt during the fall of both the Yuan and the Ming Dynasties. After the fall of the Qing Dynasty, Yunnan was ruled by autonomous warlords. The Second Sino-Japanese War saw a substantial upheaval in Yunnan, as refugees and industry fled from the occupied territories to the province.

With the rise of the People's Republic of China, much of the ambiguity surrounding Yunnan's place in China overall was finally resolved.

Yunnan in The War That Came Early
Yunnan was outside the Japanese sphere of control even into 1941. When Japan went to war with various western powers early in 1941, the British began sending supplies into Yunnan from India.

In response, Unit 113 in Burma shipped porcelain bomb casings full of cholera baccili and rodents infected with plague into Yunnan, particularly the town of Baoshan. When reports came of sickness, the Japanese air force bombed the town.

In short order, Chinese forces abandoned Yunnan, and were unable to use the British supplies.