洮河
After suffering a disastrous defeat against Shu forces at the west bank of the Tao River, Wang Jing and his remaining men retreated to Didao and took shelter inside the fortress. When Jiang Wei wanted to take advantage of the momentum to press on and besiege Didao, Zhang Yi advised him to stop advancing further because they would risk losing everything they had gained so far. Jiang Wei ignored him and ordered his forces to surround Didao.