him. Huan was impressed at Wang's knowledge and tactics, and he asked Wang why the people of the Qin lands were not shifting their allegiance to Jin, and Wang pointed out that the people were not sure what Huan's intentions were, given that he hesitated at crossing the Ba River (灞水), just east of Chang'an. As the situation stalemated, Huan began to run out of food supplies was forced to withdraw. He invited Wang to withdraw with him, but Wang declined, apparently believing that Huan was not the right person to follow. (Wang would eventually become the prime minister of the Former Qin emperor Fu Jiān a decade later.) Against Yao Xiang In 356, Huan submitted a petition requesting that the capital be moved back to Luoyang—the capital until its fall in 311 to Han Zhao - but the imperial government declined, instead ordering him to first attack Yao Xiang, who had taken many cities in the Luoyang region after rebelling against Yin Hao earlier. Huan advanced his troops to Luoyang and faced Yao in battle, and he eluded a trap Yao laid for him and dealt Yao a major defeat, forcing Yao to head west. (Yao would eventually be captured and killed by Former Qin in 357.) Huan secured the Luoyang region for Jin. He, in 362, reproposed the idea of moving the capital back to Luoyang, but the imperial government again declined. Against Former Yan For the next few years, Huan largely spent his effort in securing his power, as he invited many capable people to join his staff, including Xie An, Wang Tanzhi, Chi Chao, Wang Xun, and Xie Xuan. He did not carry out another northern campaign, apparently not willing to face the capable Former Yan general Murong Ke in battle. (Indeed, when Murong Ke's brother, the Former Yan emperor Murong Jun died in 360 and was succeeded by his young son Murong Wei, contrary to the optimism that many Jin officials had that with Murong Jun out of the way that Former Yan would be weakened, Huan commented, "Murong Ke is still alive, and I am afraid that we have an even greater problem.") In 364, Emperor Ai, who succeeded Emperor Mu in 361, suffered a poisoning after taking pills given to him by magicians in search of immortality, and Huan was initially summoned to the capital to serve as regent, but a second order