Bihwa Gaya is mentioned in the Goryeo Saryak and under the name "Bijabal" in the Japanese chronicle Nihonshoki. It may have arisen from the 3rd centuryJinhan state of Bulsaguk (불사국, 不斯國) which was probably also located in Changnyeong. Archeological evidence suggests a close relationship between Bihwa Gaya and nearby Silla, although as part of the Gaya confederacy Bihwa would frequently have been at war with Silla.
The royal tombs of Bihwa Gaya are located in Gyo-dong, Changnyeong-eup, in Changnyeong County. Some of these tombs were excavated during the period of Japanese occupation in 1918, but all records of that excavation have been lost. In 1973, a team of researchers from Busan's Dong-A University excavated several remaining tombs. These tombs appear to have been constructed in the 5th century. Some of them show indications of live burial of members of the royal household. In 1996, a museum focused on the relics of the Bihwa Gaya period opened adjacent to the tombs.
Historians of the Gaya kingdoms usually assume the existence of the so-called "six Gayas," which is taken to include Geumgwan-gaya and Ara-gaya.
The expression"six Gayas" was coined simultaneously with such words as Hugoguryeo and Hubaekje in the years of confusion between the final period of Silla and the early days of Goryeo.
As the history of the confederation of Gaya in the early days of Goryeo is unclear, it is doubtful that the seven small states of Gaya listed in Samguk-yusa were actual members of the state confederation of Gaya at that particular time.