Yeon Gaesomun (594–666) was a powerful military dictator in the waning days of the Goguryeo kingdom, which was one of the Three Kingdoms of ancient Korea. He is remembered for his successful resistance against Tang China under Emperor Taizong and his son Emperor Gaozong. Traditional Korean histories from Joseon painted Yeon Gaesomun as a despotic leader, whose cruel policies and disobedience to his monarch led to the fall of Goguryeo. However, his achievements in defending Goguryeo against Chinese onslaughts have inspired early Korean nationalist historians, most notably the 19th-century Korean historian and intellectual Sin Chaeho, to term Yeon Gaesomun the greatest hero in Korean history. In popular culture Yeon Gaesomun is often remembered as a exceptional soldier-statesman without equal in Korean history. Biography Yeon Gaesomun was born into the influential and distinguished Yeon family as the first son of Yeon Taejo, the prime minister () of Goguryeo during the reigns of King Pyeongwon and King Yeongyang. His grandfather Yeon Ja-yu was also a prime minister. Information about Yeon Gaesomun comes largely from the Samguk sagis biographical accounts of King Yeongnyu, King Bojang, and Yeon Gaesomun himself, and tomb engravings and biographical accounts, from the New Book of Tang, dedicated to his sons Yeon Namsaeng and Yeon Namsan. Tang Chinese historical records give Yeon Gaesomun's surname as Cheon ( in Chinese, meaning "water spring"), because Yeon ( in Chinese, meaning "riverhead") was the given name of Emperor Gaozu (), the founding emperor of Tang, and thus subject to the naming taboo by Chinese tradition. Yeon Gaesomun is also sometimes referred to as Gaegeum (). In the Nihon Shoki, he appears as Iri Kasumi (). Since both Yeon Gaesomun and Iri Kasumi are transcriptions from Chinese and Japanese intending to approximate his Korean name, his actual name can be reconstructed as "Eol Kasum". Very little is known of Yeon Gaesomun's early days, until he became the Western Governor (), where he oversaw the building of the Cheolli Jangseong, a network of military garrisons to defend Liaodong from Tang. Yeon Gaesomun had at least three sons: (eldest to youngest) Yeon Namsaeng, Yeon Namgeon, and Yeon Namsan. Overthrow of the throne In the winter of 642, King Yeongnyu was apprehensive about Yeon Gaesomun and plotted with his other officials to kill him. When Yeon Gaesomun discovered the plot, he arranged a lavish banquet to celebrate his rise to the position of Eastern Governor ()