Duke Zhou enjoys a lofty position in Confucian culture. Confucius said, "I no longer dream of Duke Zhou" is a metaphor for the loss of etiquette culture in the Zhou Dynasty.
Duke Zhou is a frequent figure in Confucius' dreams. In China, where Confucian culture has dominated for a long time, Duke Zhou is inevitably directly associated with dreams. Dreams are often called "dreams of Duke Zhou" or "dreams of Duke Zhou".
Therefore, the Duke of Zhou is Zhou Gongdan.