During Emperor Taizu's Reign
In 907, Zhu Quanzhong had Tang's final emperor Emperor Ai yield the throne to him, ending Tang and starting a new Later Liang Dynasty with him as its Emperor Taizu. He created his sons princes, and Zhu Youzhen received the title of Prince of Jun. Around that time, Emperor Taizu had just established a corps of imperial guards known as the Tianxing Army (天興軍), and he made Zhu Youzhen one of the two commanders of the Tianxing Army. In 910, Emperor Taizu gave him the honorary title of acting Sikong (司空, one of the Three Excellencies) and, in addition to command of the Tianxing Army, gave him the title of commander of forces at the eastern capital (i.e., Bian Prefecture, which by this point was known as Daliang, with Emperor Taizu having established Luoyang as capital).
Read more about this topic: Zhu Zhen