Goguryeo (37 BC – 668 AD) (Korean: 고구려; Hanja: 高句麗; RR: Goguryeo; lit. 'high castle'; Korean pronunciation: [ko̞.ɡu.ɾjʌ̹]; Old Korean: Guryeo) also later known as Goryeo (Korean: 고려; Hanja: 高麗; RR: Goryeo; lit. 'high and beautiful'; Korean pronunciation: [ko.ɾjʌ]; Middle Korean: 고ᇢ롕〮, kwòwlyéy), was a Korean kingdom which was located on the northern and central parts of the Korean peninsula and the southern and central parts of modern-day Northeast China (Manchuria). At its peak of power, Goguryeo encompassed most of the Korean peninsula and large parts of Manchuria, along with parts of modern-day Russia. Archaelogical evidence suggests it may have extended as far west as modern-day eastern Mongolia.
Along with Paekche and Silla, Goguryeo was one of the Three Kingdoms of Korea. It was an active participant in the power struggle for control of the Korean peninsula and was also associated with the foreign affairs of neighboring polities in China and Japan.
Goguryeo was one of the great powers in East Asia until its defeat by a Silla–Tang alliance in 668 after prolonged exhaustion and internal strife following the death of Yŏn Kaesomun. After its fall, its territory was divided between the Tang dynasty, Later Silla and Parhae.
The name "Goryeo" (alternatively spelled "Koryŏ"), a shortened form of Goguryeo (Koguryŏ), was adopted as the official name in the 5th century, and is the origin of the English name "Korea".
The kingdom was originally called Guryeo (Old Korean: 句麗, Yale: Kwulye, [ku.ɾjʌ̹]) or something similar to kaukuri), Both words were derived from "忽" (*kuru or *kolo) which meant castle or fortress. The word was possibly a Wanderwort like the Middle Mongolian qoto-n.
Several possible cognates for 忽 exist as well, which was used at a later stage as an administrative subdivision with the spelling of hwol [hʌ̹ɭ], as in 買忽 mwoyhwol/michwuhwol [mit͡ɕʰuhʌ̹ɭ], alongside the likely cognate of 骨 kwol [ko̞ɭ]. Nam Pung-hyun presents it also as a Paekche term, probably a cognate with the Goguryeo word with the same meaning and spelling.
The iteration of 徐羅伐 Syerapel as 徐羅城 *SyeraKUY equated the Old Korean word for village, 伐 pel with the Old Japanese one for castle 城 ki, considered a borrowing from Paekche 己 *kuy, in turn a borrowing from Goguryeo 忽 *kolo. Middle Korean 골〯 kwǒl [ko̞ɭ] and ᄀᆞ옳 kòwòlh [kʌ̀.òl] ("district") are likely descended from *kolo.
The name Goguryeo (Korean: 고구려; Hanja: 高句麗; Korean pronunciation: [ko̞ɡuɾjʌ̹]), which means "high castle", is a combination of Guryeo and the prefix Go (Korean: 고; Hanja: 高; lit. 'high, big'). The name came from Goguryeo-hyeon, a subdivision that was established by the Xuantu Commandery. As Han influence over Korea declined, Goguryeo-hyeon became the center of the early Goguryeo union.
From the mid-5th century, Goguryeo was shortened to the calque of Goryeo (Korean: 고려; Hanja: 高麗; Korean pronunciation: [ko.ɾjʌ]; Middle Korean: 고ᇢ롕〮, Kwòwlyéy), which by itself had the meaning of "high and beautiful".
The earliest record of the name of Goguryeo can be traced to geographic monographs in the Book of Han and is first attested as the name of one of the subdivisions of the Xuantu Commandery, established along the trade routes within the Amnok river basin following the destruction of Gojoseon in 113 BC. The American historian Christopher Beckwith offers the alternative proposal that the Guguryeo people were first located in or around Liaoxi (western Liaoning and parts of Inner Mongolia) and later migrated eastward, pointing to another account in the Book of Han. The early Goguryeo tribes from whom the administrative name is derived were located close to or within the area of control of the Xuantu Commandery. Its tribal leaders also appeared to have held the ruler title of "marquis" over said nominal Gaogouli/Goguryeo county. The collapse of the first Xuantu Commandery in 75 BC is generally attributed to the military actions of the Goguryeo natives. In the Old Book of Tang (945), it is recorded that Emperor Taizong refers to Goguryeo's history as being some 900 years old. According to the 12th-century Samguk sagi and the 13th-century Samguk yusa, a prince from the Buyeo kingdom named Jumong fled after a power struggle with other princes of the court and founded Goguryeo in 37 BC in a region called Jolbon Buyeo, usually thought to be located in the middle Amnok/Yalu and Hun River basin.
The Samguk sagi, a text from the 12th century in Goryeo, claims that Goguryeo was founded in 37 BC, but today the date of the dynasty's foundation is in doubt, as archaeological evidence suggests that Goguryeo was founded before Silla, and four things support this:
Kim Pusik was a 12th-century historian and author of the Samguk sagi (History of the Three Kingdoms). Since he was a descendant of the Silla royal family, it is likely that he distorted history to show the superiority of his ancestor, Silla, and this is undeniable.
Since Kim Pusik wrote the History of the Three Kingdoms at least 5 centuries after the events of the Three Kingdoms and was not an eyewitness to the events of that era, his book is considered a secondary source and cannot be considered a primary source alone.
The age of Goguryeo in the Samguk sagi contradicts what is inscribed in Gwanggaeto the Great's stele (which is a primary source). Gwanggaeto the Great's stele states that Goguryeo is 900 years old, but the Samguk sagi mentions Goguryeo as a dynasty that lasted 705 years.
Also, the Old Book of Tang (945), a primary source, written by Li Shimin (Taizong), mentions that Goguryeo is about 900 years old.
In 75 BC, a group of Yemaek who may have originated from Goguryeo made an incursion into China's Xuantu Commandery west of the Yalu. The first mention of Goguryeo as a group label associated with Yemaek tribes is a reference in the Han Shu that discusses a Goguryeo revolt in 12 AD, during which they broke away from the influence of the Xuantu Commandery.
According to Book 37 of the Samguk sagi, Goguryeo originated north of ancient China, then gradually moved east to the side of Taedong River. At its founding, the Goguryeo people are believed to be a blend of people from Buyeo and Yemaek, as leadership from Buyeo may have fled their kingdom and integrated with existing Yemaek chiefdoms. The Records of the Three Kingdoms, in the section titled "Accounts of the Eastern Barbarians", implied that Buyeo and the Yemaek people were ethnically related and spoke a similar language.
According to John Jorgensen, "Goguryeo was a multi-ethnic kingdom, ruled by mounted warrior tribes originating from the north in Buyeo, consisting of local Yemaek farmers and other groups, who were likely the ancestors of modern Koreans. There were as well migrants and captives of Chinese and Xianbei ethnic groups, brought in to bolster the rulers' powers in the captured territories." Book 28 of Samguk sagi stated that "many people of China fled [to] East of the Sea due to the chaos of war by Qin and Han". Later Han dynasty established the Four Commanderies, and in 12 AD Goguryeo made its first attack on the Xuantu Commandery. The population of Xuantu Commandery was about 221,845 in 2 AD, and they lived in the commandery's three counties of Gaogouli, Shangyintai, and Xigaima. Later on, Goguryeo gradually annexed all the Four Commanderies of Han during its expansion.