Muryeong of Baekje (Hanja: 武寧王; Born: 462 – Died: 523, Reigned: 501–523) was the 25th king of Baekje, one of the Three Kingdoms of Korea. During his reign, Baekje remained allied with Silla against Goguryeo, and expanded its relationships with China and Japan.
The Tomb of King Muryeong calls him King Sama (斯麻), and records his birth year as 462. The Samguk Sagi calls him King Muryeong, with the personal name (휘) of Sama (斯摩). He is described as the second son of the 24th king Dongseong. He became king when Dongseong was assassinated by the court official Baekga. The following year, he crushed a planned rebellion by Baekga.
China's Liang shu gives his surname as Yeo and personal name as Yung, and states that he restored Baekje into a strong nation. Japan's Nihonshoki gives his birth year as 461, and describes him as the son of Gonji, the younger brother of the 21st king Gaero, making him the stepbrother of Dongseong. It is said Gonji escaped the invading Goguryeo forces with King Muryeong's mother to Japan, and she went into labor as their ship was passing by a small Japanese island. He was called Semakishi (嶋君) and King Shima (斯麻王) in Japanese records because he was born in an island. Some scholars claim Muryeong ruled the Yamato region under the name of King Bu before he moved to Baekje to be a king of kings (大王).
In 501, he sent an army to attack Goguryeo's Sugok-seong. In 503, he repelled an attack by the Mohe. In 507, he successfully countered another attack by Goguryeo and Mohe forces. In 512, Goguryeo conquered two castles, but Muryeong personally led 3,000 men to destroy the Goguryeo army. In 523, he ordered the building of a fortified wall to defend the northern border.
According to both historical and archeological sources, contact and trade between China and Baekje increased during Muryeong's reign. In 512, according to the Liang shu, Muryeong sent Baekje's first mission to the newly established court of the Chinese Liang Dynasty. A second mission was sent in 521, announcing various victories over Goguryeo. In reply, the Liang emperor bestowed various titles on him, including "Great General Tranquilizing the East (寧東大將軍)" and "King of Baekje". These titles were also found engraved on a tablet in King Muryeong's tomb. In 503, he sent a bronze mirror, and in 513 and 516, Confucian scholars to Japan.
In 1971, King Muryeong's tomb was excavated in Geumseong-dong 5-1 beonji, Gongju, Southern Chungcheong Province, South Korea, where he was buried with his queen. In 2001, Japan's Emperor Heisei-Akihito told reporters "I, on my part, feel a certain kinship with Korea, given the fact that it is recorded in the Chronicles of Japan that the mother of Emperor Kammu was of the line of King Muryeong of Baekje." It was the first time that a Japanese emperor publicly acknowledged Korean blood in the imperial line. According to the Shoku Nihongi, Emperor Kammu's mother, Takano no Niigasa is a descendant of Crown Prince Sunta, son of Muryeong, who died in Japan in 513 (Nihon Shoki Chapter 17).