information:extraction, information:classification, structural:expansion, structural:scholar_edition
Decline

Allied with China under the Tang dynasty, Silla conquered Goguryeo in 668, after having already conquered Gaya in 562 and Baekje in 660, thus ushering in the North–South states period with Later Silla to the south and Balhae to the north, when Dae Jo-young, a former Goguryeo military officer, revolted against Tang Chinese rule and began reconquering former Goguryeo territories.