sentences:  In 931 AD, Dương Đình Nghệ defeated the Southern Han army – one of the Ten Kingdoms near Tĩnh Hải Quân (Army of the Peaceful Sea, the name used for Vietnam's army at that time) and achieved the independent status of the Vietnamese at Tĩnh Hải quân; he named himself Jiedushi and was recognized by the Later Tang court.In 937 AD, Đình Nghệ was killed by Kiều Công Tiễn, revoking the title of Jiedushi.Đình Nghệ's son in law and also his general, Ngô Quyền mobilized his army to exact revenge on Công Tiễn.