unsuccessful attempts to storm the fortress, Yeon was forced to withdraw and allow Yang to keep his position as fortress commander. This proved to be to his advantage. In 645, Taizong led a campaign against Goguryeo. Some Goguryeo border fortresses fell early, but Tang was unable to reduce Ansi fortress. Goguryeo sent a force reported at 150,000 to raise the siege of Ansi fortress, but the force was unable to reach it. Despite its siege of Ansi, the Tang army was unable to force its capitulation. Taizong eventually ordered the construction of a large earthen siege ramp, which Yang instead captured and used as part of his defense. When winter approached, Tang forces were forced to withdraw. The siege of Ansi fortress is related in detail (but without the commander's name) in the Samguk Sagi, Goguryeo vol. 9. (vol. 21 overall). In popular culture Portrayed by Im Dong-jin in the 2006-2007 KBS TV series Dae Jo Yeong. Portrayed by Shin Dong-hoon in 2006-2007 SBS TV series Yeon Gaesomun. Portrayed by Joo Jin-mo in the KBS2 TV series The Blade and Petal. Portrayed by Jo In-sung in 2018 film The Great Battle See also History of Korea Military history of Goguryeo Notes Military history of Korea Goguryeo people Korean generals