Biyu of Baekje was the 20th king of Baekje

Baekje

Baekje or Paekche was a kingdom located in southwest Korea. It was one of the Three Kingdoms of Korea, together with Goguryeo and Silla....

, one of the Three Kingdoms of Korea

Three Kingdoms of Korea

The Three Kingdoms of Korea refer to the ancient Korean kingdoms of Goguryeo, Baekje and Silla, which dominated the Korean peninsula and parts of Manchuria for much of the 1st millennium...

.

According to the Samguk Sagi

Samguk Sagi

Samguk Sagi is a historical record of the Three Kingdoms of Korea: Goguryeo, Baekje and Silla. The Samguk Sagi is written in Classical Chinese and its compilation was ordered by Goryeo's King Injong Samguk Sagi (History of the Three Kingdoms) is a historical record of the Three Kingdoms of...

, he was the eldest son of the 19th king Guisin

Guisin of Baekje

Guisin of Baekje was the 19th king of Baekje, one of the Three Kingdoms of Korea. He was the eldest son of King Jeonji and Lady Palsu.The traditional dates of Guisin's rule are based on the Samguk Sagi...

. The traditional dates of Biyu's rule are based on the Samguk Sagi. On the basis of more contemporaneous Chinese records, Best (1979) has suggested that the years 428 or 429–455 are more plausible.

Within the Korean peninsula

Korean Peninsula

The Korean Peninsula is a peninsula in East Asia. It extends southwards for about 684 miles from continental Asia into the Pacific Ocean and is surrounded by the Sea of Japan to the south, and the Yellow Sea to the west, the Korea Strait connecting the first two bodies of water.Until the end of...

, Biyu sought to strengthen Baekje’s relationship with Silla

Silla

Silla was one of the Three Kingdoms of Korea, and one of the longest sustained dynasties in...

, exchanging ambassadors in 433 and 434. Although Silla was a protectorate of Goguryeo at this time, Silla and Baekje allied themselves against Goguryeo (Naje Dongmaeng Hangul

Hangul

Hangul,Pronounced or ; Korean: 한글 Hangeul/Han'gŭl or 조선글 Chosŏn'gŭl/Joseongeul the Korean alphabet, is the native alphabet of the Korean language. It is a separate script from Hanja, the logographic Chinese characters which are also sometimes used to write Korean...

 :나제동맹 Hanja

Hanja

Hanja is the Korean name for the Chinese characters hanzi. More specifically, it refers to those Chinese characters borrowed from Chinese and incorporated into the Korean language with Korean pronunciation...

:羅濟同盟).