 Complete the following phrase:  the widow of an older brother. Even the local officials cannot prevent it. By the 7th century to 9th century AD, as the Tang Empire ruled over the region, historians such as Henri Maspero proposed that ethnic Vietnamese became separated from other Vietic groups such as the Muong and Chut due to heavier Chinese influences on the Vietnamese. Other argue that a Vietic migration from north central Vietnam to the Red River Delta in the seventh century replaced the original Tai-speaking inhabitants. At least 6 monks from northern Vietnam traveled to China, Srivijaya, India and Sri Lanka during the Tang period. A bronze bell inscription dated 798 inscribes names of 100 female members of a local Buddhist sect that have the middle syllable thị C. shi that corresponding to the most common form of name for Vietnamese women. In 816, Liêu Hữu Phương, a native Vietnamese scholar, traveled to Chinese capital Changan and passed the Imperial examination. In the mid-9th century, local rebels aided by Nanzhao tore the Tang Chinese rule to nearly collapse. The Tang reconquered the region in 866, causing half of the local rebels to flee into the mountains, which historians believe that was the separation between the Muong and the Vietnamese took at the end of Tang rule in Vietnam. In 938, the Vietnamese leader Ngo Quyen who was a native of Thanh Hoa, led Viet forces defeated the Chinese Southern Han armada at 