Xuanzhang was an actual historical figure.
The link above retells his story and his significance in Chinese history by bringing buddhism to China. The author of Journey to the West, Wu Cheng En named his character the Monk after Xuanzhang, much of the premise of the story to Journey to the West is based on Xuanzhang’s adventure traveling to India. The only difference is that the actual Xuanzhang traveled alone was a fugitive from the Chinese Emperor because he left China without his permission (there was a travel ban in China at the time), while in the book by Wu Cheng En Xuanzhang was granted permission and Wukong was sent to protect him from harm that would come his way during his travels.
Because the real Xuanzhang brought buddhism to China for his item I will make a large golden Buddha head lodge between clouds in the Heavens for his symbol.