Episode 13: The Korean Script Was Not Made at the Jiphyeonjeon. Hanguel is Korea's native alphabet, but how much is known about its origins? Schoolbooks in Korea claim that King Sejong the Great invented Hangeul, with the cooperation of scholars who belonged to the Hall of Worthies, or Jiphyeonjeon. But there is no evidence for this in the written records from that era. How much is accurate of what is known about the invention of Hangeul? Episode 14: Yi Sunsin: A Hero's Choice, Facing the Storm. Admiral Yi Sunsin was a brilliant strategist who took advantage of favorable geographical and battle conditions. During the seven years of the Imjin War (1592-1598) against Japan, he was undefeated in battle. Behind his hard-fought military victories were tough choices bathed in blood and sweat. When Joseon faced peril, as in the Battle of Myeongnyang and Battle of Noryang, Admiral Yi's choice was always a swift current. His strategic decisions under turbulent assured the survival of his country.