Overview
Silla adopted Tang official dress in 649, a decision that was diplomatic as much as sartorial — the court was aligning itself with the Tang in the years before the peninsular wars. The result is two wardrobes in one: the Tang round-collared robe and belt for office, and beneath and beside it the indigenous jacket-and-trousers that Korean dress had worn since Goguryeo. The bone-rank system then legislated the difference between ranks in fabric, colour and ornament, and the surviving decrees read as a list of what each rank could not use.
How it is worn
The official robe closes at the right under a round collar and is belted, with the rank shown in the belt’s fittings and in colour; the woman’s outfit is a short jacket tied at the front over a high-waisted skirt, with a long stole. The bone-rank rules cover exactly the things visible at a distance — the weave of the cloth, the metal of the pins, the colour of the outer garment — and forbid the lower ranks the silks and gold that the true-bone aristocracy wore.
History
The wardrobe is known from a small, awkward evidence base: the decrees preserved in the Samguk Sagi, tomb figurines, Buddhist painting and the objects from Gyeongju’s royal tombs. Nothing textile survives from the period in Korea. What follows in Goryeo keeps the layered jacket and skirt and lets the Tang robe drift toward its own forms, so the Silla arrangement reads in hindsight as the moment Korean dress took a Chinese official layer and kept it separate from what it wore underneath.