Wikipedia
Hwandudaedo ("ring-pommel sword") is the modern Korean term for the earliest type of Korean sword, appearing in the Proto-Three Kingdoms of Korea. These swords were at first symbols of a ruler's power, but their availability in the 5th century, and it became a more widespread symbol of military or political rank. The frequency of finds declines in the 6th century.
The hwandudaedo were large military swords made for battle, as it had a thick back and sharpened blade. This sword's name was given because of the round shape of the pommel (daedo 대도把頭). They were richly decorated, with inlay work and especially by elaborate pommel shapes. Subtypes are distinguished based on their decoration, including '' Sohwandudaedo'' (no decoration on the pommel rings), Samyeophwandudaedo (pommel ring with three opened leaves), Samruhwandudaedo (three pommel rings forming a triangle), Yonghwandudaedo (pommel with dragon), Bonghwandudaedo (pommel with phoenix), Bonghwangmun (peacock pattern), Indongdangchomun, Samyeopmun, Wondudaedo, Gyududaedo, Samruhwandudaedo, Bangdudaedo, Duchudaedo.