The infinite competition towards 21st century information-oriented and knowledge based society has begun already. Who will be the leader in this 21st century with a rapidly changing world situations? What is the real leadership in this era that can lead a family, a company, and a country? From the recent survey in Korea, Se Jong took the 1st place in "who is the person that you want to clone?" Se Jong was remembered as the best leader in the history. Who was he really?