## Overview
Daegaya (大加耶) was the leading state of the Later Gaya confederation, centered on present-day Goryeong in North Gyeongsang Province. In the ninth lunar month of 562 (the 23rd year of King Jinheung), when Gaya rebelled, King Jinheung ordered Isabu to attack it. Sadaham, his deputy, led 5,000 cavalry and first charged through the city gate, and Daegaya surrendered (dates are in the lunar calendar). The geography treatise of the *Samguk sagi* records that Daegaya lasted 520 years over 16 generations, from its founder King Ijinasi to King Doseolji.

## Background
After the [[Gwanggaeto the Great's Rescue of Silla]] in 400 severely damaged Geumgwan Gaya of Gimhae, Daegaya of Goryeong became the center of Gaya from the late fifth century. The large tombs of the Jisan-dong tomb cluster in Goryeong, their grave goods, and Goryeong-style pottery spread to Hapcheon, Sancheong, Hamyang, Namwon and other areas show that a confederation centered on Daegaya existed. In 479 Daegaya sent an envoy to the Southern Qi, and "Ha Ji, King of Garak" received an official title.

In the sixth century Baekje and Silla extended their power into the Gaya region. In 522 Daegaya formed a marriage alliance with Silla, but relations soon soured, and in 532 Geumgwan Gaya surrendered to Silla ([[Annexation of Geumgwan Gaya]]). In 554 Daegaya joined Baekje in attacking Silla but suffered a crushing defeat in the [[Battle of Gwansanseong]]. In 561 King Jinheung toured Bisabeol (Changnyeong) with his gal-mun-wang, sangdaedeung, and the rulers of the four directions, and the erection of the Changnyeong Cheokgyeongbi is considered closely related to preparations for an attack on Gaya.

## Course of Events
According to the Silla annals and the biography of Sadaham in the *Samguk sagi*, the events were as follows.

1. In the ninth month of 562, when Gaya rebelled, King Jinheung ordered Isabu to subjugate it.
2. Sadaham (斯多含), a Hwarang from an aristocratic family, became deputy commander, led 5,000 cavalry, and first rushed into the Jeondan Gate (栴檀門) and raised a white banner.
3. The people inside the fortress were terrified and at a loss, and when Isabu arrived with his troops, they all surrendered at once.
4. When merits were assessed, Sadaham ranked first. The king rewarded him with good fields and 200 prisoners of war, but Sadaham declined the fields and released the prisoners to become free commoners.

The *Samguk sagi* gives Sadaham's age at this time as 15 to 16.

## Aftermath
The territory of Daegaya became Daegaya-gun of Silla. The entry for the 23rd year of Emperor Kinmei (562) in the *Nihon Shoki* also says that Silla attacked and destroyed the Imna Kanka and lists the "Ten States of Imna," including Garak and Ara, which reflects the fact that the remaining small Gaya states were all incorporated into Silla around this time. U-rok, a musician of Daegaya, had earlier defected to Silla and taught the gayageum in Gukwon (Chungju), and King Jinheung made gayageum music one of Silla's great music traditions (daeak).

## Impact and Significance
With the fall of Daegaya, in the mid-sixth century Silla expanded its territory west of the Nakdong River and came into direct border contact with Baekje. Afterward, the area of Daeyaseong (Hapcheon) west of the Nakdong River became a front line where Baekje and Silla clashed ([[Battle of Daeyaseong]]).

## Disputes and Debates
The "Garakguk Ki" section of the *Samguk yusa* dates to 562 the surrender of King Gu-hyeong of Geumgwan Gaya, but this is generally regarded as a confusion with the date of the fall of Daegaya.

## References
- [Encyclopedia of Korean Culture, "Daegaya"](https://encykorea.aks.ac.kr/Article/E0013970)
- [Encyclopedia of Korean Culture, "Jinheung of Silla"](https://encykorea.aks.ac.kr/Article/E0055013)
- [Encyclopedia of Korean Culture, "Isabu"](https://encykorea.aks.ac.kr/Article/E0044524)
- [Korean Wikipedia, "Daegaya"](https://ko.wikipedia.org/wiki/%EB%8C%80%EA%B0%80%EC%95%BC)