Emperor Ai of Tang sibling Li Yu, Prince Di
Background
Li Zuo was born in 892, at the main palace at the Tang imperial capital Chang'an.  His father Emperor Zhaozong was already emperor at that point, and he was Emperor Zhaozong's ninth son.  His mother was Consort He, who had previously given birth to an older brother of his, Li Yu, Prince of De, who was Emperor Zhaozong's oldest son.
In 897, Li Zuo was created an imperial prince, along with his brothers Li Mi (李秘) and Li Qi (李祺); Li Zuo's title was Prince of Hui.  Later in the year, with Li Yu having been created Crown Prince earlier in the year, their mother Consort He was created empress.By 903, Zhu Quanzhong the military governor (Jiedushi) of Xuanwu Circuit (宣武, headquartered in modern Kaifeng, Henan), already previously one of the most powerful warlords in the Tang realm, had taken Emperor Zhaozong's court at Chang'an under control, in alliance with the chancellor Cui Yin.  That year, Emperor Zhaozong was prepared to give Zhu the title of Deputy Generalissimo of All Circuits, with one of his sons serving, titularly, as Generalissimo, and he initially wanted to give that title to Li Yu as Li Yu was older.  However, Zhu wanted a younger prince to serve as Generalissimo to avoid diverting the focus of authority, so Cui, under Zhu's orders, recommended Li Zuo.  Emperor Zhaozong agreed and made Li Zuo Generalissimo.In 904, Zhu forced Emperor Zhaozong to move the capital from Chang'an to Luoyang, which was even more firmly under his control.  Later that year, fearing that the adult Emperor Zhaozong would try to rise against him while he was away on campaigns against other warlords, he had Emperor Zhaozong assassinated.  Bypassing Li Yu and the other older princes, he had an edict issued in Emperor Zhaozong's name creating Li Zuo crown prince and changing his name to Li Chu.  Shortly after, Li Chu took the throne (as Emperor Ai).  Empress He, who survived the assassination, was honored empress dowager.
brother or sister kin