Unmanned hot air balloons are popular in Chinese history. Zhuge Liang of the Shu Han kingdom, in the Three Kingdoms era (c. AD 220-280) used airborne lanterns for military signaling. These lanterns are known as Kongming lanterns (孔明灯)
I capture this photo from Bangladesh. Now this is popular in here!
source:https://en.m.wikipedia.org/wiki/History_of_ballooning
I didn't know they were used for military signaling at one point, that's very interesting. Great post!
thanks :)