Commentary is pretty interesting. 不拟回头望故乡 is actually from this Chinese poem by Linghu Chu:
弓箭沐浴着霞光，宝剑照耀着寒霜。
剑起案列的秋风，驰马飞出了咸阳。
国土一角仍沦陷，天子没有收河湟。
这种情况不改变，不拟回头望故乡。
The last two lines are the crux of the poem. At this time, the Tibetan Empire occupied larges swathes of China (particularly the Hexi corridor and Dingxi region) after taking advantage of the An Lushan rebellion to pillage up until Chang'an. The speaker affirms that he shall not return to his hometown until the foreign invaders are expelled.

The picture itself has nothing much to do with the commentary except for the evocative and emotionally wrought description of never seeing one's hometown again. It's actually about Emperor Xiaowu who was the last emperor of the proto-mongolic Xianbei Northern Wei dynasty around 300 years earlier. He was forced to flee west to Chang'an with Yuwen Tai after the general who had installed him as emperor, Gao Huan marched on the capital of Luoyang (the emperor had been trying to eliminate him to escape being reduced to a puppet).

Later Yuwen Tai would poison him to death, thereby ending the last emperor of Northern Wei.