soon after emperor guangwu's ascension, his former liege gengshi emperor's regime was destroyed by the chimei, who supported their own pretender to the han throne, emperor liu penzi. the chimei leaders, despite being militarily powerful, were however even less capable at ruling than gengshi emperor, and they soon alienated the people of the guanzhong (關中, modern central shaanxi) region, which they had taken over when they overthrew gengshi emperor. they pillaged the guanzhong region for supplies, but as eventually the supplies ran out, they were forced to withdraw east in an attempt to return home (modern shandong and northern jiangsu). emperor guangwu, anticipating this, set up his forces to harass and tire the chimei out, and then block them off at yiyang (宜陽, in modern luoyang, henan). with their path blocked and their troops exhausted, the chimei leaders surrendered. emperor guangwu spared them, including their puppet pretender emperor penzi.