In 1875 on the second British expedition Mangyun, known to the British as Manwyne, was to make world history as it was here that August Margary, the consular envoy accompanying the British survey group, was killed by locals, most likely at the instigation of the local strongman and with consent of the Chinese authorities. The exact spot where Margary is believed to have been killed (马嘉理事件发生地) is one kilometre downstream of Mangyun.
Possibly the most authoritative identification is by Captain William Gill, who came through Mangyun in late 1877, only two and a half years after the incident:
Just beyond a stream we came to a hot-spring. We asked the chief if this was the scene of poor Margary's death. No, he said, but just by the edge of the water where we had crossed it. (Gill)
Two small memorials on either side of the road remember the incident today. To the Chinese official history the event marks the allegiance of the local Jingpo to the Chinese state: they killed an enemy of the Chinese court, thus affirming that Han and the ethnic minorities have a long history of friendship.
After Britain's 1852 annexation of lower Burma lucrative trade with China through its back-door seemed more than a distant possibility. But after a successful first mission up the Irrawaddy and into Yunnan in 1868, the second British mission six years later ended in tragedy.
Access is easiest with a shared taxi to Mangyun and then walk.