How far is it to Burma
The Emperor heard that Burma had offered tribute to the Yuan and thus sent Yan, together with Cheng Dou-nan, Zhang Wei and Qian Yun-gong, to go there as envoys with Imperial orders. When Yan and the others reached Annam, it happened that Champa was engaged in fighting with Annam. The roads were blocked and there was no way through. They waited for over two years but were unable to advance. An Imperial order was then issued calling them to return. At this time, only Yan returned, the others having died on the journey.
MSL, 1 Jan 1374