The Song dynasty (960 – 1279) was one of the ruling dynasties of Imperial China. Succeeding the Five Dynasties and Ten Kingdoms period that followed the Tang dynasty, the era was known for the invention and creation of many new technologies and advancements such as gunpowder, which was used by the Chinese armies.
With the rise of the Mongol Empire under Genghis Khan, China under the Song regime became embroiled in a long conflict against the northern invaders. Despite the aid of the Chinese Brotherhood of Assassins, the government ultimately fell to the Mongols under Kublai Khan in 1279, inaugurating the Yuan dynasty.
The Song dynasty was the ruling regime of China in the early 13th century when Genghis Khan unified the Mongols under his banner with the power of the Sword of Eden. In short order, he began an invasion of China and its neighbors, the Xia and the Jin. His conquests drew the attention of the Assassins, and in 1227, the Mentor of the Levantine Brotherhood Altaïr Ibn-La'Ahad traveled to China with his wife Maria Thorpe and son Darim Ibn-La'Ahad to eliminate him. On 18 August, with the help of Mongolian Assassin Qulan Gal, they assassinated the Great Khan as he was besieging the Xia capital of Xingqing. However, the Assassins failed to retrieve the Piece of Eden and it remained in the hands of the Mongols.
The war with the Mongols therefore continued unabated under Genghis Khan's successors for the following decades with the Song gradually losing more and more ground to the indomitable enemy. During this time, the Chinese Brotherhood of Assassins cooperated closely with the Song government in the defense of the nation. In 1259, the Mongols under the Möngke Khan assailed Diaoyu Castle. There, an agent of the Chinese Brotherhood simultaneously serving as a Song commander was killed in a duel against the Mongolian officer Bayan, an act that nevertheless helped to forestall a Chinese defeat.
In the aftermath, the Assassin's vengeful daughter Zhang Zhi was recruited into the Brotherhood by the Mentor Kang despite his fears over her motivations. Defying her master's orders against revenge, on 11 August, Zhi infiltrated the camp of Möngke to assassinate him. While she succeeded, she was grievously crippled in her escape. Using her injury as a pretext, Kang forever renounced her apprenticeship in spite of her having killed the founder of the Mongolian Rite of the Templar Order.
Möngke Khan's death did not save the Song dynasty as the Mongol invasions continued under his younger brother and successor Kublai Khan. In 1279, the last of the Song forces were destroyed and the whole of China fell under the Mongol Empire, who established the Yuan dynasty.
- In Assassin's Creed: The Secret Crusade, when Altaïr Ibn-La'Ahad recounts his mission to assassinate Genghis Khan, he erroneously refers to the Western Xia Empire as a province—presumably of Song China.