There was a very glorious thing in ancient China, that is, giving a surname. The emperor might give his surname to his ministers, and wealthy families might give their surname to their servants. For example, we often watch ancient TV dramas. The prime minister of this family is named Liu, and every doorman in his family is named Liu, including Liu Cheng and Liu Yu. It doesn't matter what the doorman's original surname is. As long as you enter my door, your surname will be Liu. The same is true for the emperor. If the emperor feels that you are very loyal, he might as well give you my surname. In the late Tang Dynasty, many ethnic minorities were later given the surname Li. This is why today Li is almost the most populous surname in China.
Similarly in the Ming Dynasty, in the middle of the Ming Dynasty, an emperor gave more than 120 people the surname Zhu at one time. The most famous one was the national surname Zheng Chenggong. Due to his meritorious service, Zheng Chenggong should actually be called Zhu Chenggong according to history. But among so many given surnames, there is one person whose given surname is very interesting. This is also a famous person - Zheng He, the eunuch of Sanbao. Zheng He himself was not a Han Chinese, and his surname was Ma Sanbao. Later, he was given the surname Zheng by Zhu Di, the founder of the Ming Dynasty. Why did he give the surname Zheng?
It is recorded in official history that after Ming Chengzu became emperor, he recalled his military career for most of his life, especially after the Battle of Jingnan, in Zhengcunba, which is today's Beijing. Daxing fought a fierce battle. In this battle, Sanbao eunuch Ma Sanbao performed very bravely, so Ming Chengzu was happy and said that in order to commemorate this battle, I will change your surname to Zheng, and you will be called Zheng He from now on.
Zhu Di, the founder of the Ming Dynasty, trusted Zheng He very much, otherwise he would not have sent Zheng He to the West with tens of thousands of people. Many people understood that Zheng He's voyages to the West had a very important political purpose, which was Explore the whereabouts of Zhu Yunwen along the way. This kind of thoughtful thing must only be done by a confidant. So we can infer that Ming Chengzu absolutely trusted Zheng He.