China, Early T'ang (618–626)

When Kao-tsu became emperor (reigned 618–626), he was still only one among the contenders for control of the empire of the Sui. It was several years before the empire was entirely pacified. After the suppression of Hsüeh Chü and the pacification of the northwest, the T'ang had to contend with three principal rival forces: the Sui remnants commanded by Wang Shih-ch'ung at Lo-yang,