Wang Jun, the military commander of You Province (幽州, modern Beijing, Tianjin, and northern Hebei), who had an uneasy relationship with Sima Ying up to this point, then declared war against Sima Ying and headed south with his troops, allied with various Xianbei and Wuhuan tribes. Sima Ying found it difficult to resist them, and he sent one of his subordinates, the Xiongnu noble Liu Yuan, to his own tribesmen to ask them to join him. Once Liu left, however, Sima Ying's forces collapsed. When Liu heard this, instead of bringing his forces to Sima Ying's aid, he declared independence and entitled himself the Prince of Han—claiming rightful inheritance of Han Dynasty, as he claimed to be descended from a Han princess who had married a Xiongnu chanyu – and thus establishing Han Zhao. (A month earlier, Li Xiong had declared himself independent of Jin as well, as the Prince of Chengdu, establishing Cheng Han; these two states would be the first two of the Sixteen Kingdoms.)