emperor guangwu, however, had to deal with two campaigns against non-chinese peoples. in 40, a vietnamese woman named trưng trắc (chinese: zheng ce (徵側)) and her sister trưng nhị (chinese: zheng er (徵貳)) rebelled. trưng trắc claimed the title of queen, and she ruled over an independent kingdom for several years. in 41, emperor guangwu sent ma yuan against the trưng sisters. in 43, he defeated the trưng sisters and killed them. (according to vietnamese historians, they committed suicide by drowning.)