Towards the end of the Shang Dynasty, King Zhou was a tyrannical ruler, leading to disunity among his officials and low morale in his army. King Wu of Zhou, uniting eight feudal lords from the west, gathered an army of 40,000 soldiers to march against King Zhou. Before their departure, at a solemn assembly, King Wu delivered a speech, emphasizing that everyone, from top to bottom, must be of one mind and one heart (一德一心) and vow not to rest until King Zhou was overthrown. Not long after, the Shang Dynasty was brought to an end.