“The Great King, Sejong” is a full-scale political drama describing how King Sejong and his loyal retainers cooperate and contrive to make his dynasty a better place. While King Sejong was on the throne, the Joseon Dynasty enjoyed increasing prosperity. The drama shows the dramatic processes of how so many new cultural heritages have been devised. At that time, “Hangul”, the native phonemic alphabet system for Korean language was first invented and introduced. Before it was made, Chinese characters had been used for a written communication, which makes it extremely difficult for ordinary people to learn and use. “Hangul” is easy to learn for its simple and scientific principles. Other than “Hangul” itself, there had been so many cultural heritages during his regime including a rain gauge, a sundial, an hourglass to name a few. Also, King Sejong’s pragmatic diplomacy is concentrated in the drama. Then, the Joseon Dynasty was facing a powerful Ming dynasty of China, and King Sejong demonstrates the essence of pragmatism with dignity.