Song Yun

He and his companions Huisheng, Fali, and Zheng or Wang Fouze left the Wei capital Luoyang on foot in 518 and returned in the winter of 522 with 170 Buddhist scriptures.

After passing through Wakhan, they met with the king of the Hephthalites, who had taken over the lands previously controlled by the Yuezhi and had recently conquered Gandhara.

[6] He was apparently on tour at the time near the entrance to the Wakhan Corridor and not at his capital city Badiyan (Bâdhaghìs) which was near modern Herat in western Afghanistan.

[7] The king, who had control over more than forty kingdoms, prostrated twice and received an Imperial edict from the Northern Wei Dynasty on his knees.

There are some minor discrepancies among the surviving sources as to the exact dates of the journey and the names of the people who made the trip together.