 Instead, at the suggestion of his brother-in-law Xiao Yu, the emperor sought more help from Princess Yicheng, who was one of his relatives but—according to Turkish custom—was in charge of managing military affairs at home in her husband's absence.She sent Shibi Khan a false report of a northern attack on the Khaganate; hearing this and learning of Chinese reinforcements on their way to the emperor's relief, the khan abandoned the siege and returned north.Su subsequently suggested to Emperor Yang that he return to Chang'an, but at Yuwen's suggestion, Emperor Yang went to Luoyang instead.