en.wikipedia.org/wiki/Legendary_Amazons

The film is set in early 11th century China during the reign of Emperor Renzong of the Song Dynasty. The emperor neglects state affairs and indulges in personal pleasures, while the government sinks into corruption and war continues to rage on at the borders of the Song Dynasty. The Song Dynasty is being invaded by the armies of the rival state of Western Xia.

Yang Zongbao is the last man standing in the Yang clan, a family of generals who have dedicated their lives to defending the Song Dynasty from foreign invaders. He apparently dies in battle tragically when the treacherous Imperial Tutor Pang refuses to send reinforcements to aid him. Yang Zongbao's widowed wife Mu Guiying leads the other widows of the Yang clan into battle to continue the legacy of their husbands.