While the novel itself is attributed to Wu Cheng'en (吴承恩), who lived during the Ming Dynasty (1368-1644), it's important to note that:
* The story of the Monkey King predates Wu Cheng'en. Legends and tales about a mischievous and powerful monkey figure existed in Chinese folklore long before the novel was written.
* Wu Cheng'en compiled and developed these existing legends. He gave the Monkey King his iconic personality, backstory, and role in the epic journey to the West.
* The novel is a complex work that draws inspiration from various sources. It blends Buddhist and Taoist teachings, folklore, and historical events to create a rich and compelling narrative.
Therefore, while Wu Cheng'en is credited as the author of Journey to the West, the story of the Monkey King itself has a long and complex history.