Sui


 * 1) The emporer Yang Chien was a cruel and greedy emporer.
 * 2) They failed four times to take Korea.
 * 3) They were surrounded by Turks.
 * 4) China was divided into loads of smaller kingdoms by the end of this dynasty.
 * 5) They lead several long and costly military campains and all that were aimed north failed.
 * 6) Toward the end of the Sui Dynasty, it became really unstable until it finally collapsed completely.