In the Sixteen Kingdoms period, several of the kingdoms that ruled northern China used "You" to name commandery-sized prefectures in their domain. When northern China was unified under a single sovereign during the Northern Dynasties, You became a commandery-sized prefecture based in modern Beijing. During the Sui Dynasty, prefectures were not used as a level of administration, and You was renamed Zhuo Commandery ("Zhuojun"). You was revived during the Tang Dynasty as a smaller, commandery prefecture; its capital Youzhou was within present-day Beijing. In the Five Dynasties period, You was one of Sixteen Prefectures ceded to the Khitans of Manchuria. Thereafter, the name You Prefecture was no longer used.