In 391, Tuoba Gui attacked Rouran—which had been a Dai vassal but had never submitted to him—inflicting major damage on Rouran, but was unable to destroy it.
In 391, Tuoba Gui assaulted Rouran—which had been a Dai subordinate but never submitted to him—inflicting significant harm on Rouran, yet was unable to annihilate it.