When Hergé decided to create a story that would put Tintin in China, he was advised to do more research by other, to avoid controversy. The subject of China was a very delicate matter in those times, and Hergé agreed. Sent to Hergé to help him learn more about China, Chang first met Hergé in 1934. The two men, both 27 years old, soon became fast friends, and both learned much from each other.