realizing that neither wei nor gongsun would voluntarily submit, emperor guangwu started a campaign against wei in summer 30—assisted by wei's friend ma yuan, who had served as wei's liaison officer to emperor guangwu and had tried in vain to persuade him not to take the course of independence. in response, wei formally submitted to gongsun and accepted a princely title—prince of shuoning—from him, and also tried to persuade dou to join him. dou refused, and attacked wei in coordination with emperor guangwu's forces. after some initial successes, wei's small independent regime eventually collapsed under overwhelming force and was reduced severely. in 33, wei died and was succeeded by his son wei chun (隗純). in winter 34, shuoning's capital luomen (落門, in modern tianshui, gansu) fell, and wei chun surrendered.