taekwondo1-2, Exercise 1: Subak evidence

Model answer:

Three Kingdoms: Goguryeo tomb murals (Anak Tomb No. 3, Muyongchong) show figures in unarmed combat "sometimes interpreted" as subak; similar readings of Baekje and Silla artifacts "remain debated".
Goryeo: organised matches called subakhui; the Goryeosa records Yi Ui-min rising partly through subak skill; the royal court sometimes held competitions.
Joseon: early legal codes such as the Gyeongguk Daejeon mention subak in connection with military examinations; royal annals record kings watching competitions. By the late period references decline.

Why techniques are unknown: the surviving documentation is fragmentary and often ambiguous; no technique list survives.
What the word may mean: "hand striking" or "bare-hand fighting", a general description of unarmed fighting, not necessarily the name of one clearly defined or continuous system.

Sources: Wikipedia, Subak (martial art); Korean martial arts.