Silla (Korean: 신라; Hanja: 新羅; Old Korean: 徐羅伐, Yale: Syerapel) was a Korean kingdom that existed between 57 BCE and 935 CE and was located on the southern and central parts of the Korean peninsula. Silla, along with Paekche and Goguryeo, formed the Three Kingdoms of Korea. Silla had the lowest population of the three, approximately 850,000 people (170,000 households), significantly smaller than those of Paekche (3,800,000 people) and Goguryeo (3,500,000 people) and was considered less developed and weaker compared to both Goguryeo and Paekche.
Silla was one of the longest-lasting countries in Korean history. Its foundation can be traced back to the semi-mythological figure of Hyeokgeose of Silla (Old Korean: *pulkunae lit. 'light of the world'), of the Park clan. The country was first ruled intermittently by the Miryang Park clan for 232 years and the Wolseong Seok clan for 172 years and beginning with the reign of Michu Isageum the Gyeongju Kim clan for 586 years. Park, Seok and Kim have no contemporary attestations and went by the Old Korean names of Geoseogan (居西干, 1st century BCE), Chachaung (次次雄, 1st century CE), Isageum (泥師今, Old Korean: *nisokum) and Maripkan (麻立干, 5th–6th century) instead.
It began as a chiefdom in the Jinhan confederacy, part of the Samhan, and after consolidating its power in the immediate area, conquered the Kaya confederacy. Eventually allying with Sui China and then Tang China, it conquered the other two kingdoms, Paekche in 660 and Goguryeo in 668. Thereafter, Unified Silla occupied most of the Korean peninsula, while the northern part re-emerged as Parhae, a successor-state of Goguryeo. Unified Silla was a prosperous country, and its metropolitan capital of Seorabeol (present-day Gyeongju) was the fourth-largest city in the world at the time. After nearly 1,000 years of rule, Silla fragmented into the brief Later Three Kingdoms of Silla, Later Paekche, and Taebong, handing over power to Goryeo in 935.
Until the official adoption of Hanja names for its administration, Silla was recorded using the Hundok reading of Hanja to phonetically approximate its native Korean name, including 斯盧 (사로; Saro), 斯羅 (사라; Sara), 徐那 (伐) (서나[벌]; Seona[beol]), 徐耶 (伐) (서야[벌]; Seoya[beol]), 徐羅 (伐) (서라[벌]; Seora[beol]), and 徐伐 (서벌; Seobeol).
In 504, Jijeung of Silla standardized the characters into 新羅 (신라), which in Modern Korean is pronounced Silla. According to the Samguk sagi, the name of 新羅 (Silla), consisting of the components sin (新), as in deokeopilsin (德業日新) and ra, as in mangrasabang (網羅四方) is thought to be a later Confucian interpretation.
The modern Seoul is a shortened form of Seorabeol, meaning "capital city", and was continuously used throughout the Goryeo and Joseon periods even in official documents, despite the formal name having been Hanyang or Hanseong. The name of the Silla capital changed into its Late Middle Korean form Syeobeul (셔블), meaning "royal capital city," which changed to Syeoul (셔울) soon after, and finally resulted in Seoul (서울) in the Modern Korean language.
The name of either Silla or its capital Seorabeol was widely used throughout Northeast Asia as the ethnonym for the people of Silla, appearing as Shiragi in Japanese and as Solgo or Solho in the language of the medieval Jurchens and their later descendants, the Manchus, respectively. Koreans are still known as Солонгос (Solongos) in Mongolian, which, according to popular folk etymology, is believed to be derived from the Mongolian word for "rainbow" (солонго solongo). In a paper published in 2023 regarding the etymology of the Mongolian word Solongos "Korea, Koreans," the following seven etymological hypotheses regarding the origin of Solongos have been enumerated: (1) It comes from the Mongolian word solongo meaning "rainbow"; (2) It comes from the Mongolian word solongo meaning "weasel"; (3) It comes from the Mongolian/Manchurian ethnonym Solon; (4) It comes from the name of the ancient kingdom of Silla; (5) It comes from Jurchen *Solgo(r) ~ Solho which in turn stems from Old Korean 수릿골 suɾiskol > 솔골 solkol "Goguryeo"; (later) Korea, Korean"; (6) It comes from the Mongolian word solgoi "left, east"; (7) It comes from the name of the medieval kingdom of Goryeo (via *Hoɾyo > *Solo(n)-). The authors of this paper have ended up supporting the sixth hypothesis, i.e. that Mongolian Solongos "Korea, Koreans" ultimately should be cognate with Mongolian soluγai > solγoi "left, wrong side of the body, left-handed, enemy to the east (from the perspective of the Mongols)"."
Silla was also referred to as Gyerim (계림; 鷄林), literally "rooster forest", a name that has its origins in the forest near the Silla capital. Legend has it that the state's founder was born in the same forest, hatched from the egg of a cockatrice (계룡; 雞龍; gyeryong; lit. 'rooster-dragon').
During the Proto–Three Kingdoms period, central and southern Korea consisted of three confederacies called the Samhan. Silla began as "Saro-guk", a statelet within the 12-member confederacy known as Jinhan. Saro-guk consisted of six clans later known as the Six Clans of Jinhan (진한 6부; 辰韓六部) from Gojoseon.
According to Korean records, Silla was founded by Bak Hyeokgeose of Silla in 57 BCE, around present-day Gyeongju. Hyeokgeose is said to have been hatched from an egg laid from a white horse, and when he turned 13, six clans submitted to him as king and established the kingdom of "Saro (pronounced [si.raʔ] at the time)" which later became the kingdom of Silla. However, this account was not attested during Silla times; Silla epigraphy instead mentions an obscure founding king named "Sŏnghan", while contemporary Chinese writings record that Silla originally consisted of Goguryeo refugees ruled by an unnamed king from Mahan.
In various inscriptions on archaeological founding such as personal gravestones and monuments, it is recorded that Silla royals considered themselves having Xiongnu ancestry through the Xiongnu prince Kim Il-je, also known as Jin Midi in Chinese sources. According to several historians, it is possible that this unknown tribe was originally of Koreanic origin in the Korean peninsula and joined the Xiongnu confederation. Later the tribe's ruling family returned to Korea from Liaodong peninsula where they thrive, and after coming back to the peninsula they got married into the royal family of Silla. There are also some Korean researchers that point out that the grave goods of Silla and of the eastern Xiongnu are alike, and some researchers insist that the Silla king is descended from Xiongnu. However, scholars such as Richard McBride suggest that this lineage may have been invented in the 7th century to placate Tang China, since no other inscriptions mention the claim.
The Nihon Shoki and Kojiki also mentions Silla as the place where the Japanese god, Susanoo first descended from the heavens after his banishment in a place called "Soshimori" (曽尸茂梨). Up until the liberation of Korea in 1945, Meiji era Japanese historians claimed that Susanoo had ruled over Silla and that the Koreans were the descendants of him, thus finding justification and legitimizing the Japanese occupation of Korea through the use of Nissen dōsoron. According to the Shinsen Shōjiroku, Inahi no Mikoto the brother of the mythological Emperor Jimmu was the ancestor to the kings of Silla. Another source referenced in Samguk sagi claims that a man from the Japanese Archipelago named Hogong helped build the kingdom of Silla.
In its early days, Silla started off as a city-state by the name of Saro (사로국; 斯盧國), initially founded by Yemaek refugees from Gojoseon. It also accepted dispersed people fleeing from the Lelang Commandery after Goguryeo's invasion, while later on incorporating native Jin people in the vicinity and Ye people to the North.
Talhae of Silla (57 CE–80 CE) was the son-in-law of Namhae of Silla (4 CE–24 CE). According to the Samguk sagi, Seoktalhae was the prince of Yongseongguk (龍成國) or Dapana (多婆那國), located 1,000-ri (里), northeast of Japan (?). Following the will of Namhae of Silla, he became the fourth king of Silla. One day, he found a low peak next to Mt. Toham (吐含山) and packed it with his own house, and he buried charcoal next to the house of a Japonic official named Hogong (瓠公), who lived there, and deceived him that his ancestors were blacksmiths, but the Hogong family took their home. Hogong was tricked into handing over his house and property to the Seoktalhae. During this period, Kim Al-chi, the ancestor of Gyeongju Kim, was adopted by Talhae of Silla.