In 747, when one of Emperor Xuanzong's favorite generals, An Lushan, visited the capital Chang'an to pay respect to Emperor Xuanzong, An, who was not Han, initially refused to bow to Li Heng—pretending that he was only loyal to Emperor Xuanzong and to no one else, including the crown prince, and that he did not even know what a crown prince was. Only after Emperor Xuanzong explained what a crown prince is—the reserve emperor, to succeed him later—was An willing to bow to Li Heng. This caused Emperor Xuanzong to favor An even more, but also later caused An to be apprehensive of whether Li Heng would bear continued resentment toward him over the incident.