Jia Sidao
Kublai's absence from the war front was seen by Chancellor Jia Sidao as an opportune moment, so he ordered to resume armed conflict. The Song army routed the small armed detachment that Kublai had stationed south of the Yangzi, and the Song regained its lost territory. With his ally Hulagu busy fighting the Golden Horde and his own forces needed in the north against the rival Khagan claimant Ariq Böke, Kublai was unable to focus on hostilities in the south. On May 21, 1260, Kublai sent his envoy Hao Jing and two other advisors to negotiate with the Southern Song. Upon their arrival and attempts to solve the conflict through diplomatic means, Jia Sidao ordered Kublai's embassy to be detained. Although Kublai would not forget this slight of imprisoning his ambassadors, he nonetheless had to focus on more pressing affairs with the threat of his brother and rival Khan. From 1260 to 1262 the Song forces raided Kublai's southern border which forced Kublai to retaliate with some minor incursions until 1264, when his brother finally surrendered and ended the civil war. In 1265 the first major battle in five years erupted in Sichuan province, where Kublai gained a preliminary victory and considerable war booty of 146 Song naval ships.