Koguryŏ endured for more than seven hundred years, and occupied the northern part of the Korean peninsula and the vast region of southern Manchuria. Koguryŏ excelled not only in the martial aspect but in the literary one too. A defining element of Koguryo was its openness: while it shared borders with countries of different cultural heritages like China in the west and nomadic tribes in the northwest, it aggressively and actively embraced foreign culture; not shying away from multiculturalism. Koguryŏ sent diplomatic envoys as far as Samarkand in Central Asia and students to China to learn Buddhism and Confucianism but also accepted numerous foreign immigrants into its domain. In the process, Koguryŏ developed its distinct culture after importing and digesting various elements from outside its borders, then influencing the vary same countries it had borrowed so much from including China among others. These openness and international(or global?) characteristics were based on the own independent world view of Koguryŏ and the pride in its culture. This book consists of three parts; part one describes the religion and thought of Koguryŏ, part two the society and culture, and part three the vestiges and relics. It covers the important archaeological research on Koguryŏ up to now.