Emperor Taiwu of Northern Wei
In 426, Emperor Taiwu of Northern Wei made the Xiongnu-ruled Kingdom of Xia his target. He sent his generals to attack Puban (modern Yuncheng) and Shancheng (modern Sanmenxia), while he himself laid siege to the Xia's heavily fortified capital of Tongwancheng. Tongwancheng fell in 427, forcing the Xia emperor Helian Chang to flee westward. Nevertheless, he was captured in 428 and his brother, Helian Ding, took over as the emperor of Xia.