The Hwarang (화랑 "Flower Boys") were an elite group of young scholar-warriors in the Korean kingdom of Silla. The Hwarang are credited with having spread martial arts throughout the Korean peninsula.
The Hwarang system was established by King Chinheung of Silla to strengthen his military. The Hwarang were groups of young men (usually from aristocratic families) who studied philosophy, the arts, sciences, mental and emotional discipilne, and armed combat. Through this development of strong mental, physical and spiritual training they were taught to serve as models of their culture and as chivalrous scholar-warriors. The traditions of the Hwarang influenced the history of the Korean peninsula for many centuries.
In addition to religious and philosophical instruction, the Hwarang were taught traditional dances, songs, literature, the arts, and science. Their combat skills are based upon the concept of the unity of opposites embodied in the um-yang. Their empty-handed fighting techniques were known for their blending of the hard and soft, linear and circular attacks. A linear thrust punch was said to be able to "break through the wooden armor of an opponent and kill him instantly." It is also said that they would spin-kick at such speeds that "their enemies frequently thought that the feet of the Hwarang warriors were swords." Their training included extensive practice with a wide variety of weapons. Within the military, the rank of Hwarang came to signify the position of a teacher of combat skills, commanding between 500 and 5,000 student trainees (from non-aristocratic families) known as the Rangdo.
The eighth century Silla historian, Kim Taemun noted in his Hwarang chronicle, "Sagacious counselors and loyal ministers follow the Hwarang and Rangdo; they produce great generals and brave soldiers." The ferocious fighting spirit of the Hwarang warriors became legendary, and their exploits were recorded for posterity in Hwarang poetry and literature. Like medievel knights in the European tradition, Hwarang narratives of the Silla dynasty served a backbone of Korean literature for a thousand years.
The Sulsa were an elite corps within the Hwarang. The Sulsa were trained to become particularly adept at camouflage, espionage, intelligence gathering, assassination, infiltration and exfiltration. Some sources credit the Sulsa as being key in Silla's ability to defeat Koguryo and Paekche, thus unifying the Korean peninsula.