The Battle of Baekgang or Battle of Baekgang-gu, also known as Battle of Hakusukinoe (Japanese: , romanized: Hakusuki-no-e no Tatakai / Hakusonk no Tatakai) in Japan, as Battle of Baijiangkou (Chinese: ; pinyin: Bijingku Zhzhn) in China, was a battle between Baekje restoration forces and their ally, Yamato Japan, against the allied forces of Silla and Tang China. The battle took place in the Baengma River (Korean: ; Hanja: ) or Baek River (Korean: ; Hanja: ), which is the lower reach of the Geum River in Jeollabuk-do province, Korea. The Silla-Tang forces won a decisive victory, compelling Yamato Japan to withdraw completely from Korean affairs and crushing the Baekje restoration movement.

Silla or Shilla (57 BCE – 935 CE) (Korean: 신라; Hanja: 新羅; RR: Silla Korean pronunciation: [ɕiɭ.ɭa]) was a Korean kingdom located on the southern and central parts of the Korean Peninsula. Silla, along with Baekje and Goguryeo, formed the Three Kingdoms of Korea.

Founded by Hyeokgeose of Silla, of the Park family, the Korean dynasty was ruled by the Gyeongju Gim (Kim) (김, 金) clan for 586 years, the Miryang Bak (Park) (박, 朴) clan for 232 years and the Wolseong Seok (석, 昔) clan for 172 years. It began as a chiefdom in the Samhan confederacies, once allied with Sui China and then Tang China, until it eventually conquered the other two kingdoms, Baekje in 660 and Goguryeo in 668. Thereafter, Later Silla occupied most of the Korean Peninsula, while the northern part re-emerged as Balhae, a successor-state of Goguryeo. After nearly 1,000 years of rule, Silla fragmented into the brief Later Three Kingdoms of Silla, Later Baekje, and Taebong, handing over power to Goryeo in 935.